Rude people in (grocery) stores. It pretty much goes without saying that at least once, someone will come out of an aisle into a main pathway without looking to see if anyone is coming. In this case, I'm the one that's approaching, and I have to suddenly stop to avoid running into your rude ass. :| The worst part is that they give me that "what the fuck are you doing in my way" glance, and the complete lack of an "excuse me." What a bunch of uncouth ruffians!
Kind of along the same line, at this one grocery store, I've almost had a few car accidents (none of which were due to something that I did). What makes it interesting is that it's the same thing every time, which also happens to be the same problem that I mentioned above. People come in an entrance, they get to the stop sign at the end, and instead of actually looking both ways, they just fucking go. Sometimes I don't even get a rolling stop out of them... they just drive right past the stop sign. Hell, I use a rolling stop quite often, but I'm not fucking stupid enough to ignore my duty of checking for existing traffic.
Thinking about it... people down here just have downright awful grocery store manners. Things like setting your jumbo "double wide" cart ("Look, ma! It's just like our home!") on one side of the aisle and standing on the other side while you peruse some sort of store brand canned shit.