Personally characters without any depth annoy me. Any time a character is shallow or has no goal it's just bothersome. Unless the character ends up growing and developing then it's just not interesting to read. Flat characters are another thing I find bothersome. If I write a story or fan fic then I still try to give minor characters something more to them, just to make them seem more appealing.
The stereotypical 'bossy girl'. I have always hated that character as long as I can remember. I remember loathing Blossom above the Powerful Girls and Bella from the Tweenies (this goes back a LONG time). They just interrupt, interfere and are never, ever right, unless the story is contrived in their favour! Made me, as a very opinionated girl, not want to argue things as much as I didn't want to be seen like them! Perhaps I was over-thinking!