Jimmy John's sells tasty sandwiches. The service is quick, even during the lunch rush. I got a combo with a pickle... and received not a sliver, but a huge, deli-style pickle. Oh, and they deliver, which is nice when you need a sandwich and can't leave the office, or the couch.
An added bonus is they offer free smells. These are really nice when you're not in the mood to eat, but want something satisfying.