I've had fun reading this thread today, and agree with so many of your pet peeves here. Some in particular:
Driving: the different aspects...not using a blinker, tailgating, cutting off, slow drivers, crazy fast drivers, and just all around bad drivers.
Lazy people: the ones that wait and/or drive around slowly in Wal-Mart's lot for hours waiting for that "prime spot" that will save them absolutely no time. There is no such thing as a "quick trip to Wal-Mart", no matter what you are getting.
Inconsiderate people: As Jeff mentioned earlier, examples of people not giving up their seat to elderly and/or disabled people. I'm not on busses/subways really, but I notice this while waiting at restaurants as well. This also covers Mikey's comments about cart handling in parking lots. I can't stand it when people just leave them, or send them sailing across to ram into someone's car. Another "inconsiderate people" point that really bothers me, and that I have noticed this summer, is jerks at the movies. Especially, I have noticed, junior high/high school age kids. We unfortunately got to the movie Anchorman a little late, on opening night, and had to sit down in the front seats amongst the little boogers. I have never had so much talking, giggling, getting up 100 times during the movie, and chair ramming in my life. Ruins the movie, and really irritates me. I mean, if you're going to pay that much money for a movie, and goof off all the way through it, why even go? Turds.