8. The Hulk and The Thing
In comics, sometimes crossovers amount to who would beat who? One of the most infamous versions of these questions, and the attempts to answer it, is The Hulk versus The Thing. Here you have two behemoths with super strength and a smidgen of invulnerability. The slugfests never failed to entertain, and any movie version would do the same. The best use of this would be in a Fantastic Four movie, as thats where most of the fights in the comics actually take place, usually with The Hulk cast as a villain. One neat twist would be to use the storyline from Fantastic Four #25-26, which also includes Dr. Doom and The Avengers. Its actually when FF meets the Avengers, and what a lead in that could make for the third Avengers film (because you know therell be a third).