I did forget to mention something that is common in both comics and the films based on those comics, and it's something that is really starting to annoy me:

Far too many villains hold the same capabilities as the hero. Iron Man faces a bigger Iron Man suit. Spider-man faces Venom. Wolverine faces Lady Deathstrike. Iron Man faces another guy who mimicks his technology but has some crazy whips and a bunch of robot Iron Men. Hulk faces Abomination. Thor faces Loki (not quite as bad, given the more reasonable backstory to both of them). All of them are two sides to the same coin, cast from the same mold, and in too literal a sense. Batman's polar opposite is Joker, and many could say they are reflections of one another, but the backstory and parallels are far more interesting. Superman and Lex Luthor are quite different, where one is a noble, fantastically-powered moron who is continually outwitted by a normal human with some critical thinking skills. I enjoy this interplay between protagonist and antagonist far better. Even if the comics do utilize a similar character as the bad guy, the films should probably lean more on other villains, or else find a more unique way to introduce the parallel villain.