While playing "Marvel: Ultimate Alliance", I got to thinking about costume changes. Trying to think of which Marvel and DC guys have had the most.

Stuff like "Spider-Man's spider originally had SIX legs, then switched to EIGHT" doesn't count. I think we're also going to have to exclude the X-men, since each member has had several variations of their suit. Same for the Wasp, since her gimmick is having a new costume for every issue. If we were to count sheer number of costumes, she'd be the undisputed champ of comics.

"Ultimate", alternate reality, silver age revamps, one-time costume modifications and stand-ins (Thunderstrike, USAgent) don't count. Strictly mainstream continuity guys who had their one primary costume altered significantly.

Off the top of my head, I thought of these guys:
-Iron Man (obviously)
-Thor
-Wonder Man
-Luke Cage (prior to his non-costumed Bendis days)
-Vision
-Black Widow
-Aquaman

Spider-Man and Green Lantern are debateable, since Kyle Rayner and Ben Reilly were pretty much "stand-ins".

Hank Pym and the Wasp are obvious answers to this.

Hank's had identity changes, though. The Giant-Man costume didn't replace the Ant-Man costume. As "Goliath", he did have three or four different costumes. So Goliath counts.

Wasp? Well, see above.

Does the Hulk count with his various incarnations? The Scarecrow also seems to change with every single Batman artist.

Yeah. Hulk would count. I can think of three: grey hulk, green hulk and "smart" hulk (aka, the Professor from the 90's).

Despite artistic variations, Scarecrow's still "guy in straw hat and sack over head".

Hawkeye's had about 7 versions of his regular purple outfit. They usually mess with the gloves, sleeves and that pesky chestplate. But he's really had 3 costumes overall, when you count his 1971 headband leisure suit and the 1995 Image/X-men outfit.