Za's is a pretty good lunch option on Campustown. They serve salads, pasta, sandwiches and pizza, all made to order. You can select from their suggested dishes or order your own by choosing ingredients. It's all very reasonable ($4 to $7), not great cuisine but very tasty nonetheless. To boot, the employees are all very friendly. It's just a three minute walk from my office, so I suspect I'll be going there a lot to eat.