Well, first and foremost lets get this out of the way: Iron Man 3 is probably the best acted Superhero movie ever from a whole cast perspective, setting aside individual performances like Brian Cox in X-2 or Alfred Molina in Spiderman 2; pretty much every actor delivers their performance well and the film is genuinely humorous throughout. However the plot just sucks and the action is too stupid for the actors that they hired and how they used them.
Compare directly with Arkham City and you'll find a "movie" with a better plot, much better bait and switch, much more interesting action sequences, and the courage to deal harshly with major characters. Arkham Asylum doesn't quite work as a movie but City definitely does just from the tight pacing throughout and much less backtracking in major areas. Mark Hamill's performance is superb throughout and Batman's eternal stoicism works quite well to combat his numerous foes in the picture. There's even Jaws elements in Arkham City to seal the deal. I suppose the one caveat here is that a 2:15 animated movie would probably be rejected by mass audiences.