Looks like a lot of detail has been put in from marvel as far as the costumes go, here's what I recognize so far.
Iron Man- Red and gold suit is the Mk 4 Armor
Silver suit is the Mk 1 (or 2) Armor
Blue suit is the Stealth Armor
Red and White suit is the Silver Centurion Armor
M.O.D.O.K- Gold and purple suit is the classic MODOK
Red and purple suit is MODAM
White and purple suit is the original comic MODOK
Yellow and purple with gray face is from the MODOK's 11 comic
Wolverine- Yellow and blue suit is the classic Wolverine but from the Astonishing X-MEN (2004)
Brown and yellow suit is the original/alpha flight Wolverine
Black and gray suit is the X Force suit
Blue and red suit was inspired from the Age of Apocalypse Wolverine
Spiderman- Blue and red suit is the classic Spidey from the comics
Black and white suit is the Symbiote Suit
Black and green suit is the stealth suit from more recent comics
Red and gold suit is inspired from the Iron Spider suit from the comics
Magneto- Red and purple suit is the classic Magneto outfit
Red and black suit is from the Ultimate Universe comics
Purple and red suit is from the Mutant X Universe comics
White and black suit is the Mag-F'in-Neto see
(MVC2 refrence)
Dr. Doom- Green and silver suit is the classic Doom from the comics
Black and blue suit is inspired by the Doom 2099 comics
Red and black suit is also inspired by the Doom 2099 comics
Black and silver suit is from the Old Man Logan comic
Deadpool- Red and black suit is the classic Deadpool
Yellow and Blue suit is from the Weapon X- Days of Future Now comics
Red, black and white suit was inspired by Deadpool's Weapon X outfit in the comics
Black and gray suit is from the Uncanny X Force comics
She Hulk- Purple and White suit is the classic She Hulk
Red and white suit is inspired from when she was on the Fantastic 4 in the comics
Red skinned she hulk is inspired by the Red She hulk from the comics
Black and white suit with light green hair is inspired by the Ultimate Universe comics (she's actually Betsy Ross in this series)
Thor- Black suit with silver buttons is the current Thor outfit in the comics
Black suit with gold buttons and no sleeves is inspired by the Beta Ray Bill comics
White suit with silver buttons is inspired by Thor Girl in the comics
Taskmaster- Blue suit with orange cape is the original outfit from the comics
Blue suit with white cape is inspired by the more current outfit in the comics
Black suit is inspired by Taskmaster in the Udon comics series
Orange suit is from the when he was apart of the Frightful 4 in the comics
Hulk- Green hulk with purple pants is the classic Hulk from the comics
Red skinned hulk is the Red Hulk from the comics
Gray skinned hulk is the Gray Hulk from the comics
Light green hulk with pink pants is the alternate Hulk from MVC2
Super Skrull- Black and purple suit is the classic Super Skrull from the comics
Black and gold suit is inspired by another Skrull named Rl'Nnd
Black and white suit is inspired by the Ultimate Universe comics
Sentinel- Purple and blue suit is from MVC2
Metallic black suit is inspired by the X-Men "Second Coming" story arc
Purple and red suit is inspired by the classic Sentinel
Yellow and blue suit is the "Mango Sentinel" from MVC2, see