1. B&B cheerleaders (blond & bitchy)--Not all cheerleaders are like this!
2. Native Americans who know all the old stories and traditions of their tribe to further a plot. Okay, I have a bestfriend who's NA and she knows nothing about her heritage. At least make 'em research their heritage to make it slightly different.
3. The evil clergy man. Yeah, enough said on that one.
4. The buffy replicates. Newsflash: You can't beat Buffy. Never. Stop trying.
5. The female protagonist complaining about the male-dominated world and using sexuality as a way to always get what she wants.
6. Angsty teens with no good reason to be. Can we get a sense of humor?
7. The hot jock who's suddenly attracted to plain jane.
8. This is a given, but I despise Mary/Gary Sues.
9. MC's that are written as bitches to prove their "tough."
10. Comic relief sidekicks that always have a comment. It can get annoying sometimes and feel like theirs a laugh track in the novel.
11. Cops that the MC claims are oblivious to everything. Give them credit sometimes! I've never read a YA book where the cops were helpful.
Also, I think we should have more African American characters in novels. My MC's best friend, Lara, is and she's a non-bitchy cheerleader, too. See, you don't need stereo-types!