There is a Shaw's/Albertson's I go to that sells sushi and they usually hire Japanese chefs to make them. If you come in at the right time, you can actually watch them make it. Somedays they have the raw stuff, but I see a lot of the already cooked fish.

I've also had the pre-packaged Sushi at Wal-Mart and Hannaford. They both suck and the rice dries out too fast. The only good international food at Hannaford is Pocky.