1. Wet towels. If they are ANYWHERE other than hanging up, it makes me frustrated. I don't care where they are hanging (designated hook, towel rack in bathroom, top of the door), I just can't stand when someone (coughNICKcough) piles them on the bed or the floor. They will not dry right and then you can really only use them once. And, let's be honest, who REALLY wants to wash towels three or four times a week, not me.
2. When I'm eating bite sized foods (goldfish crackers, M&M's, skittles, popcorn), it really bothers me to have my chewing uneven (like 2 goldfish on one side of my mouth, and 6 on the other). It is random, and totally ridiculous, but I have to make sure that I have an even amount of food on both sides of my mouth. Don't ask me where this even comes from, it's just something that I do.