Kinda depends on where you're staying and what you're in the mood for.
The Flatiron is terrific, the Drover for old-school steak, Riveras (out west) or about any restaurant on south 24th street for Mexican, Bonefish, though it's a chain, does seafood fairly well. La Buvette in the Old Market for French bistro-y fare. Hartland Barbecue. Crescent Moon for decent bar food and a colossal beer selection.