I think my major problems are with books that:
1) Tell the same stories over and over again with slight variations;
2) Have "stories" that are pretty much little more than connective tissue between fight scenes;
3) Have artists who can depict nothing but fighting, so a character walking down the steet looks like they're in a fight, eating looks like a fight, kissing looks like a fight, etc.
4) Have little ambition beyond keeping a franchise going (see #1).
These tend to plague your average superhero book more than anything else, but it's hardly unique to that genre.