I am naturally a fast walker because I don't like to waste my time walking from point A to point B, so people who walk slow and block up the whole sidewalk are really annoying. This also goes into driving, as you can probably imagine I hate getting stuck in traffic.
Also, anything that has to do with non-handicapped people using handicapped things. Obviously if you have a legitimate disability I am all for getting you the help you need. But, you are not more special than anyone else. I don't care that it's cold out for your precious self, don't park in the handicapped parking spot to have a shorter walk into the store. People who push the handicapped button to open the door to my dorm because they are too lazy to pull it themselves, then go on the elevator rather than walking up 1 flight of stairs to get to the second floor.