MVC3 What I would do to it.

Marvel:
Spider-Man (yes)
Captain America (yes)
Wolverine (yes)
Magneto (yes)
Hulk (yes)
Iron Man (yes)
Deadpool (yes)
Storm (yes)
Thor (yes)
Dormammu (yes)
Phoenix (yes)
Abomination "She-Hulk"
Punisher "Taskmaster"
Silver Surfer "Super Skrul"
X-Man "M.O.D.O.K"
Mimic "Shma-Gorath"
Scarlet Witch "X-23"
Emma Frost "Sentinel"
Apocalypse "Doctor Doom"

New:
Nova (yes)
Daredevil"Rocket Raccoon"
Scorpion Venom "Hawkeye"
Dr. Strange (yes)
Ghost Rider (Maybe)
Iron Fist (Maybe)

Capcom:
Akuma (yes)
Albert Wesker (yes)
Viewtiful Joe (yes)
Dante (yes)
Arthur (yes)
Amaterasu (yes)
Morrigan (yes)
Felicia (yes)
Zero (Yes)
Ryu (Yes)
C.Viper (yes)
Jill Valentine (yes)
Chris Redfield (yes)
Nero "Trish"
Captain Commando "Nathan Spencer"
Killer7 "Tron Bonne"
Guy "Mike Haggar"
Gene/God Hand "Hsien-Ko"
Seth "Chun-Li"

New
Strider (yes)
Vergil (yes)
Nemesis (yes)
Sieg Wahrheit/Chaos Legion "Firebrand"
Phoenix Wright (Maybe)
Frank West (Maybe) 
 
 Other People I would want