I want the typical "boring" (awesome) picks like Cyclops, Nightcrawler, Venom, Magneto, Rogue.
I really want Super Skrull back. I know this isn't Marvel 4 but he's really cool in mvc3.
I also want picrel in either this game or Rivals. Maybe give him the ability to fuck with the opponent's assist order. Shadowcat would be cool too but she'd probably work better in Rivals.