With my OCD's, I may have just cornered the market.....
Lists: I have to make them, or else I might forget something.
Placement of things: I hate clutter! If I can't find something because it's been moved, that drives me insane! Especially whenever I'm at work, and get stuck doing the dishes. If someone else has been there, and I don't like where they put things, or things are just chock-a-block, I want to pull my hair out!
Music: This is a biggie. I hate overplayed crap! Hearing the same songs three or four times a day, especially if the songs suck donkey balls, is NOT COOL! I also hate it when I song I don't like gets stuck in my and repeats on a endless loop(this is commonly referred to as an earworm).