Whitlow's on Wilson, 2854 Wilson Blvd., Clarendon; 703-276-9693. Hamburger with fries, $6.50. Served between halves of an untoasted, spongy bun, Whitlow's circular patty looks more like it was sliced from a roll of ground beef than shaped by hand. Served closer to medium-well than to the medium-rare requested, it was pleasant but not as flavorful as the best burgers on this survey. Its accompanying fries had languished too long under a warming lamp.