Mark's Duck House? (Annandale)
Mark's is reliable Hong-Kong style,excellent with some and featuring a whole bunch of weird dishes not often seen(jellyfish salad, braised frog casserole,etc.)
Reasonably cheap, seafood tanks in the back with fresh fish, sea cucumber, crab and lobster. Good barbecue meats and duck tongues are excellent and cheap. Chinese family joint basically, but try some of the fried dishes and soups especially. Also, just across Rt. 50 is Fortune, which has probably the best dim sum in the area.Go early on Saturday or Sunday or risk getting cold stuff and a three -hour wait.