I had some soup from Aubon Pain the other day and I'm definitely hooked on the stuff. My favorite is broccoli cheddar. Its not too filling and its a lot healthier than the many fast food chains I have around my area. They have a wide variety of soups if broccoli cheddar isn't your cup of tea. They have chicken noodle, italian wedding soup, tomato, and some other more unique kinds.
Au Bon Pain is really tasty, convenient food. I wish they had more locations, but there aren't too many outside of Cambridge.