Captain America

Captain America is every kids dream: going from skinny kid to jacked muscle jock without any of the annoying working out. He most often leads the Avengers, hitting people in the face with his shield. Because America!

Rogue UPDATED!

This is a (much better!) update of Rogue's X-Men Legacy costume.

Vision

Vision is a 'synthezoid' and a member of The Avengers, who managed to get the Scarlet Witch pregnant (with twins!) despite being basically a robot. He can alter his density, becoming impenetrable or intangible, can fly, is super strong and can fire energy beams from his eyes.

The Hulk

Hulk? Hulk smash. Hulk smash puny Banner.

Storm - Uncanny X-Men

Storm is still a mutant, still one of the X-Men and still controls the weather.

Siryn - X-Factor

Siryn can scream really loud, just like her dad Banshee. Also that somehow allows them to fly, because of comic book reasons. For a while she was a member of Jamie Madrox's mutant 'detective agency' and wore this no-costume costume.

Agent Brand

Agent Brand is half alien/half mutant, and a character from Joss Whedon's run on Astonishing X-Men. Marvel doesn't really know what to do with her currently, since they've given her job and role in the comics to Captain Marvel (Carol Danvers), so she mostly just seems to wander around the S.W.O.R.D. space station (that's Sentient World Observation and Response Department).