I don't know if there's many characters mentioned here that I actually consider overpowered, as that term implies that they would be better off as weaker than they were. Doctor Manhattan wasn't overpowered because his being that power was absolutely key to the character. Much the same, I don't consider Superman overpowered because I think he works best as the superhero who you know is always going to win.
Wolverine is a good point. I'm divided about Doctor Strange because he's only overpowered when he isn't going up against cosmic mega-threats and the like.
"HOW CAN YU TRET MEH LIKE DAT"