Ugly chicks who start thinking they're good looking just because they have a hot friend... I kid, I kid. =P
People who dont understand the concept of personal space. Bugs the **** out of me when someone gets too close or touches me (even if it's just their arm brushing mine) when I've made it clear I dont want them that close. For the most part I dont mind but some days you just dont want anyone near your "bubble."