Post- Play dinner
Is your play a matinee or an evening performance? What day of the week are you going? These facts would make a difference as to which restaurants are open. For example, Lattanzi is not open on Sunday.
Also, since there are literally hundreds of restaurants to choose from in the Theater District, it would help us narrow down the suggestions if you would be more specific about what you are looking for.
1. What cuisines do you prefer?
2. Do you want casual or something fancier?
3. What is your per person budget? And tell us if that figure includes drinks (wine, liquor), tax, & tip.
Three options of the more upscale variety:
dbBistro Moderne (mentioned below by alyssi) is 4-star chef Daniel Boulud's take on French bistro cuisine.
LCB Brasserie (fka La Cote Basque) offers chef/owner Jean-Jacques Rachou's first rate versions of French classics in a setting with very handsome decor.
Town serves superb New American cuisine in a gorgeous subterranean dining space.
Enjoy the show and Bon Appetit!