I have plenty, but some of my main ones:
- The heroine reforming a jackass through the power of her love and devotion. Sorry, sweetcheeks, if he's a jerk to you in the beginning of the book and in the middle of the book, he's going to be a jerk to you at the end of the book. If they didn't know their behavior was unacceptable until the heroine called them on it, that's one thing, but if he's truly a jerk, no amount of love will change him.
- Author Tracts. They can be done well, but the ones that grind the action to a halt while we hear all about how everything the author thinks is good is perfect for humanity, and everyone else is just stupid and evil.
- Getting lost in details. I'm fine with details that add to a story, but I don't need the genealogy of the cat sitting on the wall to appreciate that it's an alley cat.
- Informed flaws. When it's obvious through the text what the character's flaws are, but the author keeps going 'No, no, their only flaw is this!' Key example, Edward in Twilight. We're told his only flaw is being overprotective. We're shown that he is overbearing, controlling, sulky, possessive, jealous, arrogant, nosy, unreasonable, manipulative, whiny, and sexist. But we're supposed to ignore all of those flaws because the author tells us he's just overprotective.
- When the heroine can not make a mistake. This seems especially common in post-feminist fantasy and science fiction (presumably because of fears of being labeled sexist), but I've read so many things where the heroine does one boneheaded thing after another, it turns out all right through sheer luck, and everyone praises her for her amazing wisdom and insight. It's just as sexist to not let female characters have any consequences for their mistakes and make them perfect little special snowflakes capable of doing anything, while the men are all bumbling fools who were lost without them.