Uh, bad comic book movies? There's a lot of them.
I haven't seen Catwoman or Elektra, so I can't say anything about those but Batman and Robin is really bad. It's so bad, it's not even funny anymore. You know the phrase: "so bad it's good"? Well, Batman and Robin crossed that line almost twice, but only almost
Spider-Man 3 was really dissapointing, as was X3. Daredevil gets worse everytime I see it.
The 3rd Turtles movie was also pretty stupid. If you sent the Ninja Turtles back in time to feudal japan, you could at least try to put the foot and Shredder in it in some way
I liked both, Sin City and 300, but on different levels. Sin City is a great comic-to-screen adaption, 300 is just loud dumb fun