It would be helpful to know your cuisine and neighborhood preferences as well as your per person budget for food (beverages, tax & tip additional). But that said...
I would suggest Le Parisien, the teensy French bistro, on 33rd, b/t Lex & 3rd. Charming and cozy, red wine a-plenty, and very good food.
Le Parisien photos here: http://www.flickr.com/photos/11863391@N03/sets/72157625618994937/with/5322820451/
163 E 33rd St, New York, NY 10016