Too many options to list without something to narrow it down. What kind of food do you like? What level of formality? What price range?
The first option that comes to mind, if only because it's a nice walk across Lafayette Park, but the food is also fabulous, would be Oval Room.
Central is a short 5-block walk, but would be another contender because everyone likes the food there. (French, informal, with an American twist.)