Recent ones:
Fat chicks that dress in really tight stuff. While I give them points for having enough confidence to wear things like that, I really don't think it looks sexy on them. It looks rather bleh. Before anyone thinks it, I don't mind fat chicks, there are just some things that they shouldn't be wearing.
Two-faced people. These kinds make me rage so much. My boss is like this, and I really have to bite my tongue when she's trying to hold a conversation with me because I know she doesn't particularly enjoy my company. I know she doesn't like me, so I don't know why she has to try to be all buddy-buddy with me.