Source: comicvine.gamespot.com

9. Acts of Vengeance

I love Acts of Vengeance.

It may be the most fun of the Marvel Crossovers. I wish they'd do a sequel.

The crossover premise is fairly simple. The Marvel Universe villains are sick and tired of being beaten up by their respective heroes, so they come up with a plan to fix things. They’ll swap opponents! For example, Ultron might try to beat up Daredevil, and Doctor Doom could take a crack at Iron Man. We haven't seen a lot of villain comebacks in the MCU (because a lot of them are dead), but it would be super enjoyable to see all the Avengers split up and then have to fight each others' past foes.

Maybe Justin Hammer could come after Spider-Man with his army of drones. Or Vulture might attempt to take out Iron Man. Or they could do Captain America vs. The Abomination. Sounds fun as hell, if you ask me.