Quite naturally, there would be "our" world - as well as other fictional universes. However, let's try to stick to ideas that can pertain to the BTTF Universe.

Kristen Sheley and Mary-Jean Holmes has mentioned a bunch of them in their dimensional hopping fics. Flaming Trails also did some drabbles88 fics about possible universes. Then, of course, she and I have all our AU series.

Now, these aren't alternate timelines that are influenced by Doc and Marty mucking around in time - but just events that naturally occurred in the timeline.

Here are a few:

1. George and Lorraine don't meet - and, this time, a time-travelling Marty isn't involved.

2. Doc does end up taking on one of Dean Wooster's projects, and ends up marrying Jill.

3. Marty does end up bringing a sports almanac back to 1985. With all due respect to Kristen Sheley, I disagree with her idea that Marty might become corrupt. I prefer Flaming Trails' take on that idea.

4. In the new timeline (Marty's events in 1955 are still the same as from the movie), Marty is born as a girl. I did flirt around with that idea - but I could never figure out what would happen to her, after Doc unveils the time machine... or after Marty returns from 1955.

5. The DeLorean derails, and Marty is stuck in 1885. Of course, this is covered in Kristen Sheley's Hill Valley Chronicles series - and it was the last universe visited in No Place Like Home. I don't think it woul be fair for Doc to try to keep Marty away from girls, though. If Doc can live it up in the Old West with Clara - than why can't Marty. Especially as Marty doesn't even like the Old West as much.

6. Doc never reads Jules Verne. Kristen Sheley covered that in No Place Like Home - and Mary-Jean Holmes wrote a fic of what would happen if Clara (if I remember correctly) was to go back in time and interfere with that event.

7. Marty ends up missing the lightning bolt, leaving him stranded in 1955. Of course, I've done a rather controversial take on that scenario - where Marty gets amnesia, and marries Lorraine. He eventually becomes his own father.

8. Doc and Clara end up returning to 1985 with Marty in the DeLorean. It was covered in Kristen Sheley's No Place Like Home, and Flaming Trails and I wrote stories covering that idea. It's actually how I would've preferred for the trilogy to end.

9. Marty has a twin in the new timeline (the events of Marty in 1955 are the same as in the movie). Quite naturally, my Twins Universe.

* Marty gets himself erased from existence. I don't think that'd quite work, though - because, in Part II, Doc mentions that such a paradox could blow up the entire universe. I guess it wasn't mentioned in Part I, because Doc '55 didn't yet consider that theory.

Just a few to start out with.

BTW, what are your thoughts about the "dimensional incompatability" thing? I was never too fond of that concept. I much prefer the idea of being able to visit other dimensions witout wory.

Here are some more that Flaming Trails has done drabbles88 of:

red = Marty dies in the train crash upon returning to 1985.
black = This technically doesn't count, but Doc has a dream where Marty goes Emo.
birth = In the new timeline, Marty (Martina) is a girl.
rebirth = Emmett is the teenage science nerd, and Marty is an aging rock star.
dark = The Addams family moves to Hill Valley.
who = Her take on amnesiac Marty dating Lorraine in 1955. (She disagreed with the take that Eternal density and I took on that plot device.)
if = Doc marries Jill Wooster- and is now divoced.
choices = Marty brings the sports almanac back to 1985, and uses it responsibly.
home = Doc burns down the garage, while Marty is visiting in 1955.
grey = This is a crossover with Stargate. Apparently Trilogy Canon, with the reference to Doc dying twice.
pink = This is a crossover with Alice In Wonderland and Corpse Bride.
found = This is a crossover with World of Darkness.
years = Doc adopts Marty.
lunch = This is a crossover with Harry Potter.
transformation = The DeLorean transforms into a giant alien robot.

That last one you mentioned is a Transformers crossover -- I'd seen the movie that night, and got inspired.

"Pink" falls more under my muse universe, so I'm not entirely sure it counts. (It's a followup to "He", which takes place at the Inkwell Bar.) Of course, all my muses have their own parallel universes for the most part:

Doc: NonTrilogy (Doc never takes Marty and Jennifer to the future)
VampDoc: Vampire Doc Chronicles (above, plus vampires are part of Hill Valley)
VampDoc2: Night and Day (vampires are part of Hill Valley, Part III goes WAY differently because Doc and Marty are both transported to 1885, no train)
DocWolf: A world where animals evolved, not humans (like Kevin and Kell or JACK)
OckDoc: OckDocumentary (starts out like NonTrilogy, then variations on Parts II and III happen in 1986, involving both Marty and Jennifer)
TeenDoc: "Boy Genius" (Hill Valley transported back in time and to Europe, in a world where the industrial revolution gave rise to Mad Scientists -- Girl Genius crossover)
RolePlayDoc: Our very own old roleplay topic! :happydoc: Would be Trilogy if a bunch of meddling time travel organizations hadn't gotten in the way.
HatterDoc: BTTF!Wonderland (Wonderland from "Alice In Wonderland," only with BTTF characters in the main roles)

And that's not counting a lot of the other stuff I've written. I think I'm crossover/alternate universe crazy :D

Out of yours, I have to say that my favourites are the Boy Genius and BTTF!Wonderland Universe. It's interesting how you place all our beloved BTTF characters in an entirely different setting. Looking forward to reading Cinder-Marty, as well! :)

So far, I've kept the basic setting for my BTTF Universe the same - including the fact that the Docs from all the universes (except maybe Gravestone) have lived identical lives up until November 5 of 1955 (in his originating timeline, at least). I've just written about what would happen if certain events occurred differently. Even though, I did flirt around with the idea of putting the Keaton family in Hill Valley - or finding a way to fuse the BTTF Universe and the Family Ties Universe. It could be possible. The only minor thing you need to tweak is one very tiny plot-irrelevent piece in the Cafe '80s scene from Part II.

Anyway, here's what I have so far:

Trilogy Universe: Well, nothing is changed here.

Twins Universe: Marty gains a twin in the new timeline, after returning to 1985. He accompanies Doc and Marty oin the trip to 2015, in place of Jennifer.

Newlyweds Universe: The original Marty Wept story is an alternate take on the "letter" scene, which later makes Doc more receptive to bringing Clara back to 1985 with them.

Almanac Universe: Draws from the perspective of the Hell Valley versions of Doc and Marty. They end up with counterparts in the "normal timeline".

Parker Universe: Jennifer accompanies Marty on his first time travel trip, and then plays a bigger role in the subsequent trip featured in the trilogy. Comes back from 1885 wih Clara Parker.

Haven Universe: Also a trilogy-compliant universe, but Haven being born one year earlier causes the future to be different - namely the new appearance of Marlene McFly, the addition of Melody McFly, and the strange situation of Jamie Brown.

Twin Pines Universe: In this universe, Marty was shot dead by Libyan terrorists - and was eventually (along with Doc) brought back to life.

Father Universe: My rather controversial take on an amnesiac Marty marrying Lorraine, and becoming his own father. The new Marty has a twin (Artie).

Lone Pine Universe: Marty Jr gets his hands on Doc's DeLorean, and takes it back to 1985. He brings it upon himself to warn his father about the accident.

Gravestone Universe: My take on the future of the Doc Brown who sees his gravestone.

Calvin Universe: Marty is renamed Calvin, while older brother Dave is renamed Marty.

Oops, I guess there is one universe where I put the BTTF characters in a different setting:

Orwell Universe: The universe based on George Orwell's dystopian novel, 1984 - and includes certain BTTF characters. Marty McFly doesn't exist in this universe, though. Doc is (surprisingly) a Prole, George and Lorraine are Outer Party members (and not married), and Biff is (fittingly enough) a thought police member.

I don't think Marty accidentally preventing his parents from meeting would create a paradox, just erase him from existence.

Well, this is where the trilogy contradicts itself. Of course, it's possible that Doc could be wrong about a paradox blowing up the entire universe. Then again, I guess the paradox Doc was referring two in Part II was more complex than the one referred to in Part I. Still, the theories expoused in Parts I and II do seem inconsistent - and is there really such a thing as a "little paradox" and a "big paradox"? Wouldn't it make more sense to just say a paradox is a paradox? Now I'm getting confused thinking about.

On a side note, I might have to rethink my logic concerning the Gravestone Universe. There seems to be no cut and dried answers for that one. Also, was there ever a Twin Pines Mall/Eastwood Ravine timeline? It's so confusing.

My Universes-

Mainstream Universe: Trilogy Canon

Twin Pines Universe: Original Timeline. Doc gets killed and Marty never goes back in time.

Hell Valley Universe: Biff-horrific timeline. Pretty much my interpretation of it.

Orwell Universe: Based on 1984.

Wooster Universe: Doc takes up one of the projects and marries Jill.

Retro-Futuristic Universe: Based on first draft script. How people in the '50s envisioned the '80s.

Lorraine Tannen Universe: George and Lorraine never meet and Lorraine ends up marrying Biff.

Sounds good! Then you were also going to have your Trilogy Universe Doc and Marty hop through my Twins Universe and Almanac Universe?

That's correct.

So, which project is your Doc going to take up? I guess Xerox would be the most ideal - but Doc doesn't trust companies that don't spell their name "correctly". Yeah, I agree with Flaming Trails that I can't exactly see him taking up chemical warfare. So I guess it would be the car.

I guess, in Retro-Futuristic Universe, Marty would be three years older? Does he still look like Michael J Fox? Is he going to become a rock star? Personally, and I know some may bite my head off for saying this - but I don't see any harm of Marty introducing songs by other artists into the world. After all, this world is missing a lot of rather great music - and it's be nice for Marty to correct that. If he has two sets of memories, though, then he might have a slightly easier time adjusting to that world.

Marty is going to be the same age in the retro-futuristic universe. He will still look like Michael J. Fox. Marty does have two sets of memories so it will be easier for him to adjust.

As for what project Doc takes up, you'll just have to wait and see.

Sounds good! In my fic, I had to change the auto company option - since the one the script had wasn't around in 1946.

So is Marty a rock star in the Retro-Futuristic Universe, but a more well-together type of rock star? While Trilogy Marty may feel sorry for Retro Marty in a few years, as he had to return to a very unfamiliar world (without rock and roll) - part of him may envy Retro Marty, who is the founder of rock and roll in that world.

Marty is starting a new type of music called 'Rock and Roll.' He and his band have a really hard time trying to find a producer, because their music is too different.

Oh, yeah, that'd make sense. Of course, your version would take place much earlier than Kristen Sheley's did - so he wouldn't have had as much time to establish hiomself as a legend.

His band also has a different name. I haven't decided what it would be yet. I can't see any band in the '50s calling themselves the Pinheads, so Retro Marty's band would obviously have a different name.

Yeah, that's what I figured. Even if they were The Pinheads before Marty went back - I can't see Retro Zach, Billy, and Joey (or whatever name you pick for them) agreeing to the idea. It'd be very interesting if their band's name had the word "quartet" in it.

I think I'll call them The 4 Clubs. I thought about the 4 Kings, but there's already one called The 3 Kings. And the 4 Spades is kinda racist. (Spades is a derogatory term for blacks)

Their first rock album has these songs:
Blue Suede Shoes
Hound Dog
Rock around the Clock
Johnny B. Goode (Marvin later tells Chuck against it in the retro universe)
Happy Days (You guessed it, the Happy Days theme song)
The Longest Time (Written in 1984, but has that 50s feel to it)
Rock and Roll is Here to Stay
Blue Moon

Sounds like a good idea. Do they have plans to include stuff from the '60s, the '70s, and the '80s on their future albums?

Although, I have the Happy Days theme song is from the '70s - but has a '50s feel to it.

They do have '60s, '70s, and '80s songs on their future albums. I think Marty Jr and Harmony would like this universe, because the 2010s would be more like our '80s.

Oh, yeah, probably so. So I guess they're 30 years behind in the pop culture? In a few ways, you have to feel so bad for Marty - returning to a very unfamiliar world.

Yeah. One good thing about it is that Rap might never be invented.

That's true! Also, with having a second set of memories that would probably be a litte stronger than his original memories - Flaming Trails agrees with us in that area - the adjustment would probably be a little easier for him.

Some people don't agree with the second set of memories thing. Some have him not have any recollection of what happened in the new timeline except for the stuff that stayed the same. Others have him only have a few new memories come to him in dreams, but they didn't feel real.

Aaron Jenkins seems to be the most vehemently opposed to the "new memories" thing - even though Kristen Sheley never used it in her fics, either. With Mary Jean Holmes, I know she did do the "new memories" thing in her fics, but I don't remember exactly how it worked.

I think, with Anakin McFly, the old memories eventually either fade away completely or almost completely. She also believe that LP Marty retains his LP memories upon entering 1955 - but I don't like that theor as much, because it would mess up a lot of the events from the first movie.

But, yeah, I don't like the idea of either Marty disappearing - so I'm mostly in favor of the "fusion" thing, where TP Marty and LP Marty eventually become the same.

Of course, for Jamie Brown of the Haven Universe, she had the hardest time of coping with the dual memories thing.

Biff's "love life" is going to be different in all my universes.

In the trilogy universe, he and his wife divorce and he gets the kids.

In the Twin Pines universe, he and his wife divorce and his wife gets the kids.

In Hell Valley, he married his first wife, then Marilyn Monroe, then Lorraine. He doesn't have any kids of his own.

In my retro-futuristic universe, he's still married because people in the 50s didn't get divorced.

In my Orwell universe, he never got married.

In the Lorraine Tannen universe, it's self-explanatory.

Now that sounds interesting! Actually, I think divorce has been around since the 1940s - but it wasn't as common back then. I mean, don't forget that Ronald Reagan divorced Jane Wyman. It was a mistake that Doc thought they were still maried in 1955.

Divorce has actually been around forever. But only rich people got divorced back in the 40s and 50s. Even in the 60s and 70s, it was still uncommon.

In the end, it does make more sense to have dual memories - as opposed to remembering only the final timeline. Like, what if Marty stayed in 1985 or 1986 - while Jules and Verne took a trip to 1975, and interacted with Marty's younger self of that year. Then what would Marty, who wasn't along on the time travel trip, remember?

One problem I have with Kristen Sheley's take on the whole memories thing is, while it seems like the time travellers' memories never update to the new of the most recent timeline - in No Place Like Home, it seems to be implied that Doc did eventually remember dressing Marty up in that outfit (even though he didn't remember right when he saw Marty in 1885). So I kind of see a little consistency in that. It's her ficverse, and her stories are generally enjoyable - even though the Hill Valley Chronicles series kind of depresses me - so I won't quibble too much.

The problem I have with remembering only the original timeline is when you look at it from the perspective of those native to that time. It would be like they lost the Marty they knew and love forever, to be replaced with this new Marty they didn't grow up with. It especially hit me strongly, when I was writing Twins In Time.

I just had another idea. You know how, in an earlier script, one of Biff's gang members had the idea to invent a "rollerboard". Maybe, in a universe, they actually do attempt to do just that. It'd be interesting to see how that'd work out.

Hey, Needles, I have another idea for a parallel universe - if you're interested. You could maybe include the ASOUE Universe. Actually, for my fic, I might have the Quagmire triplets be the children of Lorraine Baines. It's not something I'd be writing until later next year, though.

Thanks, but no thanks. I don't really know much about ASOUE.

I've read three of the books so far, and watched the movie. It's actually pretty interesting, even though I was initially resistent.

I decided to have Wooster and Lorraine Tannen take place in the same universe. I have another idea for one where Marty gets stuck in the 50s and is forced to live the rest of his life as Calvin Martin Klein.

Those sounds like good ideas! I say, go for it! :)

In the Calvin Klein universe, Lorraine finds local Marty and keeps questioning him on where he's been because he's been missing for nearly two months. Marty keeps telling her that he just left the house this morning.

Does Marty end up getting married in the Calvin Klein Universe, and possibly have a son the same age as the younger Marty?

He does get married and his son is older than Marty. He doesn't look like Marty either, or it would raise suspicion.

Oh, okay, that makes sense. I just thought it'd be neat for Marty to have a twin, that's all. :)

Marty and Doc will be visiting your Twins and Almanac universes. Originally, I was going to give Calvin Klein only a daughter, but I like the idea of passing on a family name that was never his to begin with. I also liked the idea of giving Marty a son who's chronologically older than him. I was going to have him be a love interest of Linda, but that would be creepy because he's her nephew. So I decided to have him be a good friend of Dave's.

Well, now that you put it that way - the irony is pretty interesting. :)

I know I haven't done much writing this week. I was busy reading the ASOUE series. I should be able to get more writing done next week. Later on, I'll explain to you the idea I have for a ASOUE/BTTF connection.