[Boy Blunder]

Oooh, I am so jumping on this list thang.

High-priority:
Marrow
Siryn
Rachel Summers
Random
Cecilia Reyes
Anole
Surge
Rockslide
Lady Deathstrike (Messiah Complex-era design)
Madelyne Pryor (Mutant X design)
Bloodstorm
Wild Thing
Skullfire
Reignfire
Exodus
Thunderbird (John Proudstar)
Sunfire (Mariko Yashida, Exiles version)
Mimic (Exiles version)
Nocturne (any costume)
Destiny

Mid-tier:
Ka-Zar/Shanna/Zabu
Lady Deathstrike (classic outfit)
Maggott
Joseph
Rogue (Modern green-and-white outfit w/ hooded cloak)
Holocaust/Nemesis
Cerebro (Hunt for Xavier design)
Bastion
Callisto
Rictor
Archangel (blue-and-white outfit, metal and/or feathered wings)
Havok (classic outfit)
The rest of The Six (from Mutant X)
The Nasty Boys
Mellencamp
Senyaka
Colossus (Acolyte outfit)
Storm (First Appearance)
Cable (Joe Casey-era blue-and-yellow costume, with psimitar weapon)
Elixer

Low priority:
Domino (90s armored costume)
Albert & Elsie-Dee
Venus Dee Milo
Dead Girl
Sage
Magma
The Hellfire Club
Negasonic Teenage Warhead (modern design)
Meggan
Arcade
Cerise
Revanche and/or armored Psylocke
Captain Britain (modern Betsy version)

Probably many, many more that I'm forgetting. I'm always a slut for X-Men toys.