I've got 3 major ones. They make my head want to explode. I'll list them in the order of how much they annoy me.
1. When I am talking to somebody and ask a question and I know the person I'm talking to heard me but they don't respond. It's not rhetorical, answer me dammit!! Liam and Jeff both do this to me often and wonder why I get so exasperated.
2. When........people......write..............like...........this. Do they even realise how much longer it takes to write like that? Use some punctuation, I'd take a whole paragraph full of exclamation points rather than have to read something with excessive use of elipses.
*disclaimer-there is one person who can get away with it in my books, but she's my sister and I love her and so I don't say anything.
3. Writing things on the computer in text-speak. Ur nt kewl. I actually know lots of people who do this and for the most part they're awesome people but this just annoys the ever-loving shit out of me ;)
Okay done with my little rant.