In the entire BTTF trilogy, we see 7 Tannens:

1955 Biff: A dangerous, bully 17-year-old.

TP 1985: A 47-year old bully supervisor, but probably not quite as bad by now.

LP 1985: Wimpy auto detailer. Probably still a mean backstabbing butthead at times, but due to his life-altering in 1955, he's not as bad as before.

1985-A: Corrupt, rich and evil. Enough said.

LP 2015: By this time, being a nearly 80-year-old man and living a less than ideal life has turned him into a grump again, not surprisingly.

1885 Buford: Evil, not unlike 1985-A Biff, but (luckily) even dumber, so he'd be easier to outsmart.

2015 Griff: A ziphead who probably has committed some big time crimes in the past, but still not quite as bad as Buford or Biff-A.

I think it's almost entirely agreeable that 47-year-old Biff-A is the worst of them all, followed closely by Buford.

I would say the least bad (intention-wise) is LP 1985 Biff. Sure, I think he'd still be a jerk, but he'd back down in an instant if you challenged him. I think 2015 Old Biff (his older self) would be the least bodily dangerous, just because he's old and probably too weak and slow to be as much of a threat anymore.

:lol: We-ll I was actually going to say that when I saw the topic heading but you've already said it!

I agree that he's the nastiest Tannen as he's quite happy to commit murders without too much sweat and then happily pay off his police so he gets away with it.

Sends a shiver down your spine, doesn't it! :( *brrrr*

I'd say the most dangerous Tannen is the one we haven't seen: Griff's father (or unwed mother, as some theorize). I mean, we have NO IDEA what this person looks like! He/She could be anyone! At least with the others, you can start running if you see them coming your way, but you wouldn't know this one until it's too late.

Probabably in this order:
1985-A Biff
1885 Buford
2015 Griff
1955 Biff
TP 1985 Biff
LP 1985 Biff
LP 2015 Biff

I agree with what the OP said.