Next to maybe Walgreens, Gamestop is the biggest PITA store for toy hunting, at least in some ways. It's impossible to slip in and out unobtrusively, the sales staff is either aggressive or ignores you completely, their average time per transaction is 200% higher than any other store I've ever been to because of all the upselling they are forced to do, and at least around here they open late and close early compared to other stores.
On the plus side, there are lots of them, you can track store inventories effectively via their website, and they will reserve stuff for you if you ask.