A few have come to mind.
Domino
Kitty Pride
The White Queen
Mystique
Lady Deathstrike
Iceman (maybe with his 90's look?)
Shatterstar
CARNAGE (the old one is still Great, but he needs a modern touch- Removable mask, Chaotic sharp tendrills/hands)
ULTRON
oh, and most of all
Wolverine (All of them. AGAIN)