Every Batman story ever written by Frank Miller. I despise his treatment of the Batman mythos with a vengeance, which is pretty sad, since I like his creator-owned work.
The 1993-1999 Superman comics. I know the Continuity Police assert that this is the only proper way to write and depict Superman, but it's too cookie-cutter, too one-note, too shallow, too gimmicky, and too blatantly stupid for my tastes. That the comics haven't improved much since the end of this era speaks volumes about how stagnant DC's become.
Anything by Bendis. He's all yakking and hype and no substance. He bores me to death.
Post-Marston
Wonder Woman. If she's not watered-down and made goofy/girly-girly to the max, she's a character-less cipher whose surroundings and supporting cast change every single time a new creator comes along. What was wrong with what Marston gave her? Oh, yeah, forgot. Anything before 1986 is the Great Satan. My bad.
X-Men. I like the movies. I like the concept. But the comics are too gimmicky and overstuffed for me. I just can't into that kind of overly busy level of convolution.
The various Punisher books. He works fine as a supporting character and in mini-series. But on an regular basis he gets real old, real fast. Building a whole line of books around him was one of Marvel's dumbest ideas.
Image's superhero stuff. Aside from Alan Moore's
Supreme, evything that came out of Image at the peak of the McFarlane/Lee/Liefeld period was generic boring crap. I get far more enjoyment out of the humor comics like
Liberty Meadows,
Player Vs. Player, and
Desperate Times.
Anything by Mike Kaluta and Gary Gianni. Their art styles are just too messy and busy for my liking. (Kaluta didn't use to be like this, but as time goes on...yikes.) I'm only buying the second volume of the collected Conan stories that Gianni's illustrating because I like Robert E. Howard's writing; I'm just going to have to overlook Gianni's art on that one.
Swamp Thing. I just don't think he's all that great a character.
There's more, but I won't bore you with it right now.