You can go to the online store @ GAP too. They do carry some of their stuff in sizes 18-20/XXL. The store carries up to size 16/XL. Here's the link:
GAP Online
I'm pretty sexy for a 16-18

and I like to show my body (appropriately, now)...but I feel everybody's frustration when you go to some of these stores and the clothes are all big and baggy and stuff. So I appreciate all the sites that have been posted up so far. I've seen some nice ones, too bad I do not have a credit card!! But I'm sure that I can get a catalogue or something.