Cyclops. One of the most brilliant tactical minds in the Marvel Universe, an extremely powerful mutant, and eternal nice guy who is the punchline to everyone's jokes because he plays by the rules.
I'd love to see him say "fine, the hell with the rules and the hell with you", blast Wolverine's head off and toss it into the sea, then go off on his own. Let him do some villainy where he really turns his powers loose, blasting buildings in half and whatnot. Show everyone how much he's been restraining himself, and let him be the character he deserves to be. Then, a couple of years down the road, he can join a team that actually respects his leadership, restraint, and compassion.