I live in a town heavily populated with retirees. There are lots of folks who have no business being on the road, and yet, they're driving. Some of them can barely see over the wheel!!
I can't stand when people don't bother to straighten their cars out in parking lots, or park on corners so they obstruct the view.
People turning right on red who are so concerned with getting to turn that the neglect to see the pedestrian in the crosswalk (I once actully smacked someone's car to get the driver's attention--I figured better that than have him hit me).
Drivers who hold up traffic while looking for their turn, or almost cause an accident b/c they're about to drive past it. It's like turning around is illegal or something.
Someone mentioned not returning the carts to the collection thingie. Last week, we went to Lowe's. There was a cart in the stall right next to the return! And the return wasn't full!!!
Women who wear low-rise pants and short tops so the "muffin top" is on full display. Same with any pants where I can see your undies or your backside, whether or not you're bending over.
I realize this makes me sound old and out-of-date, but I don't care. There are just some things that are better left unshown.
Rude shop owners.
People who abuse their animals/kids. And if the animals were never socialized, the rescuers have an incredibly difficult time handling/treating them. If the animal is lucky enough to end up in a no-kill location, then it'll have a place--otherwise, it's "unadoptable" and euthanized. (I spend a good portion of every Saturday with several animals that weren't socialized, and really want to tie their former "owners" outside with little to no human contact for months on end.)