The part that gets me is when they try to get me to buy a used copy of whatever I bring to the register. Thrifty is nice, but if I want a game disc that looks like somebody ice-skated over it and a chimpanzee with a palm full of lard played twister on it, then I'd go straight to the used shelf.
And yeah, as mmntech says, their rates are horrid. Buy a game for barely a few bucks less with marks on it? No thanks. I was even there when somebody bought a game "new" and he walked out of the store and opened it. Smart move, there was a giant thumb-print on the surface. Probably not enough to ruin the disc, but when you pay good money for a "sealed" game, why settle with used goods? Do the employees rent the games before release or something?
And lastly, mouthy, know-it-all employees. I turn into a major rager (inwardly) when I hear the employees belittle other companies while talking to customers when THEY work for the bottom of the barrel game retailer. That and when they are completely wrong about games which haven't been released or other facts. I keep my mouth shut, but I know I've done more homework than these guys.
No offense to Gamestop employees that post here. I'm talking about 1 of 2 local gamestops in my area. I've been to the other one once, it was nice and quiet.