As a person who grew up with the X-Men comics and later on the TV show, i've been playing X-Men games since i was 8 in 1990.
Best:
Wolverine X-Men Origins for PS3 and Xbox360.
Arcade X-Men.
X-men Legens 1 & 2.
X-Men Next Dimension.
X-Men 1 & 2 for Genesis.
Marvel Superheroes for Arcade and PS1.
Marvel vs. Capcom 1 & 2.
Street Fighter vs. X-Men.
Mutant Academy 1 & 2 for PS1.
X-Men: Children of the Atom for Saturn and Arcade.
X-Men Mutant Apocalypse for SNES.
Fair:
X2: Wolverine's Revenge for PS2.
X-Men Mutant Wars for Gameboy.
X-Men 3: Mojo World for Gamegear.
Mediocre:
Wolverine for NES.
Wolverine: Adamantium Rage for SNES.
Worst:
X-Men for NES.
X-Men/Spider-Man Arcade's Revenge for SNES. (Stinkin' Laughing Joking Numbnuts LJN)
Best:
Wolverine X-Men Origins for PS3 and Xbox360.
Arcade X-Men.
X-men Legens 1 & 2.
X-Men Next Dimension.
X-Men 1 & 2 for Genesis.
Marvel Superheroes for Arcade and PS1.
Marvel vs. Capcom 1 & 2.
Street Fighter vs. X-Men.
Mutant Academy 1 & 2 for PS1.
X-Men: Children of the Atom for Saturn and Arcade.
X-Men Mutant Apocalypse for SNES.
Fair:
X2: Wolverine's Revenge for PS2.
X-Men Mutant Wars for Gameboy.
X-Men 3: Mojo World for Gamegear.
Mediocre:
Wolverine for NES.
Wolverine: Adamantium Rage for SNES.
Worst:
X-Men for NES.
X-Men/Spider-Man Arcade's Revenge for SNES. (Stinkin' Laughing Joking Numbnuts LJN)