For somewhat healthy/filling food, try Venti's bowls on Court and Liberty St. Lots of rice, stir-fried chicken, vegetables in all sorts of styles with teriyaki, thai peanut or other sauces.
Also for great lunch/dinner/drinks, hit up the new La Capitale on State and High for stylish food that's better than you'd expect. Great value and good service.
La Margarita on Trade and High street is a long-time standby for fast sit-down Mexican fare with impeccable service. Standard Mexican fare, but the ingredients are always fresh and the value is good.