1. Bad art. In this modern day, with all sorts of advanced drawing and CG tools, you'd think it'd be possible for people to draw better than an epileptic four-year-old armed with a Crayola before they tried to release something commercially. I'm not expecting a Matisse, but five minutes of work before slapping some unidentifiable crap on a webpage is not too much to ask.
2. Baby talking. I'm probably the only one, but this drives me ****ing insane. I've never heard a funny joke told by a mushmouthed adult pretending to be prepubescent, and I've never heard an actual child who sounded this stupid.
3. **** jokes. Very funny. Didn't we grow out of these at 14, when we started realizing girls didn't have cooties? It's a bit late for the anal stage to appeal to me personally.