Here's the list (which isn't complete, anyway), with
thanks to Paul O\'Brien X-MEN AND THEIR ALLIES:
Archangel, the Beast, Bishop, Cable, Caliban, Cannonball, Lila Cheney, Colossus, Cyclops, Dazzler, Domino, Forge, Emma Frost, Gambit, Gateway, Havok, Husk, Iceman, Karma, Kylun, Leech, Lifeguard, M, Magma, Marvel Girl, Micromax, Madrox, Nightcrawler, Nocturne, Kitty Pryde, Psylocke, Rogue, Sage, Shatterstar (if he's a mutant, and his entry expresses some doubt), Siryn, Tabitha Smith, Storm, Strong Guy, Sunspot, Thunderbird (the Indian one), Warpath, Pete Wisdom, Wolfsbane, Wolverine and X-23
OTHER MAJOR SUPERHEROES:
- Aurora, Northstar (who apparently isn't undead after all), Diamond Lil, Madison Jeffries and Persuasion from Alpha Flight
- Big Bertha, Flatman and Squirrel Girl from the GLX. (No mention of the other two team members - Mr Immortal and Doorman - but on one view, current continuity has their powers deriving from Oblivion anyway.)
- Firestar and Justice
- Molly from the Runaways
- Franklin Richards (who used to be in Power Pack, so yes he IS a superhero)
- Ricochet from Excelsior
- Skein, formerly the Gypsy Moth, who was briefly a Thunderbolt
THE NEW MUTANTS AND OTHER STUDENTS:
- Elixir, Icarus, Surge and Wallflower from the New Mutants
- Hellion, Dust, Mercury, Rockslide and Wither from the Hellions
- Kid Omega
- The Stepford Cuckoos
- Anole, the gay reptile kid
- Blindfold, the telepath from ASTONISHING.
- Bling! and Onyxx from Gambit's X-MEN squad.
- Ernst, whose "Cassandra Nova" origin story has suddenly reared its head again. Somebody's finally read the comics!
- Glob Herman, the skeleton in the translucent body.
- Hisako Ichiki, the psychic exoskeleton girl from ASTONISHING.
- Martha Johansson, the disembodied brain
- Loa, a little known character with phasing powers
- Match, a pyrokinetic
- Pixie, the girl with butterfly wings
- Quill, the porcupine boy
- Trance, an astral projector
- Wolf Cub, the boy from the Dominant Species arc
SUPERVILLAINS:
- Avalanche
- Black Box, who used to be Commcast
- Jamie Braddock
- Joanna Cargill from the Acolytes
- The Dark Beast
- Empath from the original Hellions.
- Exodus
- Fever Pitch and Sack from Gene Nation
- Selene, Sebastian Shaw and Shinobi Shaw of the Hellfire Club
- Lady Mastermind, the daughter of the original Mastermind
- The Living Monolith
- Mammomax from Exodus' Brotherhood
- Arclight, Prism, Scalphunter and Scrambler from the Marauders
- Mentallo from Weapon X
- Dragoness and Tempo from the Mutant Liberation Front
- Mystique
- Mikhail Rasputin
- Omega Red
- Random
- Sabretooth
- The Silver Samurai
- The Toad
- Whirlwind, an occasional Avengers villain
RANDOMS AND NONENTITIES:
- Alchemy, the character from the "create a mutant" contest in the 1980s.
- Beautiful Dreamer and Erg, two of the surviving Morlocks
- Tatiana Caban and Kiden Nixon from NYX
- The Collective Man, national superhero of China
- Mr M, Jazz and Lorelei from DISTRICT X
- Litterbug from the MORLOCKS series a few years back, which is apparently canon after all despite taking place in a dystopian worldwhere Sentinels zap every mutant who steps above ground
- Outlaw from AGENT X
- Peepers, Frank Tieri's favourite minor character
- Rhapsody, who once met X-Factor in the early 1990s
- Sabra, national superhero of Israel
- Vanguard and Ursa Major of the Soviet Super-Soldiers
- Amelia Voght
- Evangeline Whedon, the X-Men's lawyer