I like the idea of MachineGames making a Punisher game. They've got a great feel for brutal gunplay and more grounded characters. I would say id, but they still prefer fast-paced arena gameplay, but MachineGames slows things down.
As far as a more out there idea, Riot Games making a League of Legends-style X-Men game. Plenty of Champions, or Mutants, to choose from to put on full display their abilities.