Inconsiderate drivers trying to be considerate by waving you into their lane oblivious to the people passing them on their right. Hello moron! I move and get rammed by someone passing you it's MY fault.
I also think there should be a special level of Hell for people who don't drop their hi-beams no matter how many time I flash them to do so.
My biggest peeve though is the state of movie theaters around here. People talking on cell phones, chatting away with their friends, and I've even seen some kid getting a bj from his gf right behind me AND, one couple who couldn't be bothered to take their baby into the restroom and so proceeded to change their baby's diaper ON THE FLOOR OF THE AISLE! This, combined with sticky floors, dim projector bulbs, misframing, misfocusing, revolting bathrooms, parking lot hooligans, and mischanneling of the sound (going into a DTS or Dolby certified theater only to get the film in stereo or even mono) have made me swear-off movie theaters in my area. They are all universally bad. I haven't been to the movies in two years.