-Joanna Dark (So Snake isn't alone in all his realisticalness)
-The Elite Beat Agents
-Andy/Max/Jack from Advance Wars, can call other characters from the game for his special attacks, and his super can be a whole bunch of tanks/ships/airplanes/whatever unleashing a bevy of missiles and junk. That would be awesome.
-The guy with the yo-yo from Star Tropics
-Toad
-Megaman
-The Dog from Duck Hunt