X-Men Legends/X-Men and allies

Beast
Can roll around to attack enemies.
 * Playable

Colossus

 * Playable

Cyclops

 * Playable

Emma Frost

 * Playable

Gambit

 * Playable

Gateway
He isn't a playable character. He creates portals for the X-Men to use in the game.

Iceman

 * Playable

Jean Grey

 * Playable

Jubilee

 * Playable

Magma
She is the main character in the game.
 * Playable

Nightcrawler

 * Playable

Professor X
Professor X is only available in the first Astral Plane mission.
 * Playable

Psylocke

 * Playable

Rogue

 * Playable

Storm

 * Playable

Wolverine

 * Playable