Marvel and DC fans are very vocal. If they don't like something, they take it to a very Stage-5 nerd rage place. Especially when it comes to casting their favorite heroes and villains.

But sometimes, the fans rejoice and nod approvingly from their race car bunk beds at the Hollywood stars appearing in their favorite comic books-turned-movies -- like Paul Rudd in "Ant-Man."

From "Iron Man" to "The Dark Knight," here are 18 casting choices that earned fandom's approval.