When in Northern Virginia I always look for the closest Wegmans. I really like going to their food bars and putting together an eclectic variety of oriental foods to take back to my room and feast on.
If you have never been to a Wegmans, you must give it a try. It is a large grocery stores with huge selections of everything from wine, cheese, deli meats, produce, cheese and more. The stores also have a huge variety of take home food, and even an area to sit and eat.