45. Heroes vs. Villains (Secret Wars)
I got some general votes for Heroes vs. Villains in Secret Wars, but I’m going with the specific battle that got the most votes (and counting all the votes for that as representative of “Heroes vs. Villains”), which is the fight in Secret Wars #8, which also was the first appearance of Spider-Man’s black costume!
Earlier in the War, the Wasp was killed. The Avengers want to go take on the villainous murderers, but Captain America does not think they can stop monitoring Galactus, who appears ready to devour the Battleworld they’re all stationed on.
She-Hulk goes it alone, then, and obviously gets beaten badly (I mean, duh, one She-Hulk <>
The heroes want to go rescue her, but Cap still can't agree to leave. However, the X-Men show up and say they'll watch Galactus. That allows Cap to lead the heroes on an assault on the villain compound, and the heroes proceed to destroy the villains.
Jim Shooter and Mike Zeck handled the creative duties, and there are some notable scenes, but probably my favorite is the bit where Hawkeye takes down Piledriver of the Wrecking Crew (or was it Bulldozer? One of the loser duo of the group) with an arrow.
After the battle, the heroes used a machine to repair their costumes, and Spider-Man uses a machine he THINKS is the clothing repair machine but is actually a (bear with me here) prison holding an evil symbiote that attaches to Spider-Man and becomes his new black costume.