The Guardians of the Galaxy

It may be quite some time before this kind of team-up could happen, but just think of how fun it would be for Peter Parker to fight alongside someone like Groot or Rocket Racoon! Furthermore, Peter's personality would jive incredibly well with Peter Quill's, and his sarcastic quips would go right over Drax's head (though nothing goes over his head, because his reflexes are too fast).