Decorations! Fourth of July, Thanksgiving, Halloween (ok,you can get stuff now, but 13 years ago there was nothing!) It's expensive here and you really have to trawl around for American stuff. Also wish I had a flag pole. I've got a flag but can't get my hands on a pole and it's on my list for the next time I go home.
I always bring back-Sudafed(the American one is more effecitive and cheaper), fun plasters for the kids, aloe vera gel-just starting to appear in shops but it's expensive. imitation vanilla extract-in the big plastic bottle. (the tiny bottles here last me about a fortnight).