I can only pick ONE! LOL!
Then, I would have to say "rude, inconsiderate people,' because this includes people who talk loudly on their cell phones in public, people who drive while talking on the cell phone, people who don't use turn signals, people who don't use common courtesy like saying "thank you" or "excuse me," people who throw cigarette butts or even soda cups out their car window (I saw two of these yesterday), people who cut in line, people who talk in movie theaters (a main reason why I have Netflix!), people who call a wrong number and hang up after you say "hello" instead of saying "sorry, wrong number," telemarketers who call early in the morning, the a-holes who come into my dead-end street and turn around by driving onto my front yard/flower garden...