Not to mention like a ton i did'nt name off hand, there are such better options than just Venom.
Sandman -
Easy enough, I guess. Equal strong and fast, probably a playstyle similar to Venom, though, maybe with a little Shuma Gorath in for good measure. Hammer fists and the like would be there, obviously. Can't think of a finisher, though.
Electro - A cross between Gambit and Magneto. One of his specials would be to shock the ground, and maybe have some lightning spikes come from the ground.
Shocker - I'm thinking this would be a cross between Ryu/Ken and Balrog from the SF lineup. Lot of straight punching charges and fist moves, but with the added aftereffect shocks as projectiles. Huge ass shockwave ala Omega Blast as a finisher.
Doctor Octopus - Omega Red. I'd like to see something different, but I can't begin to fathom how he'd work in a game like this. I've checked some MUGEN vids, and well, they look kinda ridiculous.
Rhino - Obviously some charging moves, probably a stomp. Moveset would probably be similar to E. Honda from Street Fighter, meets Paul Phoenix, but slower, like Hulk.
Kraven - Zangief meets Blanka, with a little King from Tekken. Nuff said.
Mysterio - I'm thinking a cross between Jin from MvC2, Strider from MvC2, and Morrigan. Lotta fast ninja-like moves and disappears, but with the added projectiles and buffs from his gizmos.
Green Goblin - His movement is Joker-like [DC/Mortal Kombat], with a few obvious specials such as bombs and such. Finisher would be calling the glider, shooting a rope to grab you, flying up to the very top of the screen, attaching a Pumpkin Bomb to the rope, and letting you fall on it, for fall and blast damage.
Hobgoblin - Similar to above, but with with more emphasis on the physical side of violence.
Kingpin - Juggs, like I said earlier.
Chameleon - No clue. A distinct brawler, perhaps? Guile without projectiles, but with the added bonus of "shapeshifting" to mimic another characters movesets and appearance, ala early Shang Tseung.
Morbius - Dmitri from Darkstalkers with a bit of Captain Commando, and obviously a move that drains life.