I hate people who don't realize that preference is subjective. "You like that band? They SUCK!" ...uh...yeah, everybody likes different things, try opening your mind a little. Why is it always about being better? Coldplay is better than U2! U2 is better than Coldplay! Whatever, I think they're both great bands. If you like them...awesome. If you don't...awesome. I just hope you get as excited about what you're listening to as much as I enjoy listening to what I like.
But my biggest pet peeve is tailgaters. I commute for an hour to work each day, and it pisses me off that people will sit 2 feet behind me while travelling at 135 km/h. Waiting at a stop light for 2 minutes will surely eliminate any of those precious seconds you saved when you swerved around me. I'll move over and let you pass if I have the opportunity, just give me some space so I don't fear touching the brakes. And what about rubber-neckers? Why are people so fascinated with accidents that they must slow down to look? Hoping you might get lucky and see a dead body or something? Maybe try focusing on the road so you don't end up in the same position!