Old Asian women with glasses in the fast lane that talk on cell phones.

That and illegal immigrants. I've been in three accidents (fender benders, thank God) in as many years, and each time it was a non-licensed, non-insured Mexican woman. I'm still pissed about "the Governator" not supporting that bill to give illegal immigrants licenses (especially considering that it would have made my insurance bill drop like a brick off a four-story building).