Spider-Man
Spider-Man villains (Venom, Green Goblin, Doctor Octopus, etc.)
Wolverine
Magneto
Captain America
Iron Man
Hulk
Rogue
Psylocke
Gambit
Juggernaut
Sabretooth
Cyclops
Colossus
Iceman
Other X-Men (Nightcrawler, etc.)
Other X-Men villains (Mr. Sinister, White Queen, Mystique, etc.)
Red Skull
Baron Zemo
Abomination
Leader
Iron Monger
Mandarin
Other Hulk villain
Other Captain America villain
Other Iron Man villain
Other supporting characters (Black Cat, War Machine, etc.)
Doctor Doom
The Fantastic Four
Other Fantastic Four villains (Anhilus, Mole-Man, etc.)
Thor
Loki
Other Thor character
Daredevil
Elektra
Bullseye
Kingpin
Other Daredevil character
The Punisher
Ghost Rider
Blackheart
Other Ghost Rider characters
Doctor Strange
Shuma Gorath
Dormamu
Other Doctor Strange characters
Deadpool
The Runaways
Howard the Duck (:P)
Other Avengers (Vision, Scarlet Witch, Hawkeye, etc.)
Ultron
Other Avengers villains
Thanos
Silver Surfer
Galactus
Adam Warlock
Other cosmic character (Firelord, Captain Mar-Velle, etc.)
Other character (???)
I didn't pick Marvel...