This is my first post, but i noticed that nobody has really mentioned Ty the Tasmanian Tiger. I used to love that game as a kid, and i think he would fit perfectly into this game, with the likes of Ratchet & Clank. I dont know that might just be me, but i think it would be cool.
While I agree that Ty would be awesome, he doesn't exactly have the history behind him to make it in. Also, I believe that it wasn't an exclusive. Although, he does have quite an array of moves that could be used well.