I hate when people cut you off to turn into your lane, and then you look in your rear view mirror and there isn't a car for miles...they couldn't of waited for one more fucking car?
When people turn out in front of you but don't hit the gas...if your going to cut me off slightly fine...we have all been in those "omg I an never making a left out of here" but HIT THE FUCKING GAS AT LEAST!!!
People that think yellow lights mean "Stop or you will get aids"
People who either A) are oblivious to your blinker and the fact that you need to get over for whatever reason or B) are dicks and don't let you in because...well they are dicks. You can let your foot off the gas for 6.2 seconds so that I can sneak in front of you to get off a certain exit? I always let people in front of me if they need to get over...its really not that hard.
People that don't give a little wave when I go out of my way to help them out, like stopping so the massive line of cars behind me don't make the person sit there waiting all day to make a turn. I always give a little wave.