If it is every Spider-Man character fighting each other, Spider-Man wins, because he could use his intelligence to turn them all against the strongest ones and such. For instance, he could turn Rhino, Electro, Smythe, Lizard and Shocker against Doc Ock or something, that way they take out the biggest threats and kill themselves in the process. Venom and Carnage automatically fight each other on the side since they're always doing that. So Spider-Man stands by and watches, then when the biggest threats are taken out, he kills the easy ones like Chameleon.