Washing machines!! !
When they spin, it drives me nuts. My washing machine isn't on perfectly flat ground either, so it tends to wobble when it spins, so not only have I got the very loud spinning noise to deal with, but also the "bangbangbangbangbang" as it seesaws up and down on the floor.
I also hate forks on plates, dishes clashing, doors being slammed, noises people make when they eat, people other than me typing on keyboards, hoovers, screeching brakes, car/house alarms, the music on Sky Digital when you leave it on TV guide, and loads more that I can't remember.