I really appreciate the fresh, healthy options Au Bon Pain provides at The Cleveland Clinic -- too often hospital food isn't really all that healthy. The salad bar has a great selection of fruit, grains, and nuts, which I piled high into my to-go container (my total rang higher than $10!) and ended up eating for two filling meals that day.
On a slightly less healthy note, their pastries are wonderful, and their massive selection is discounted after a certain hour of the day.