Some of NYC's best restaurants participate in a promotion called "Restaurant Week." Until Labor Day, Monday through Friday only, more than 100 places will offer three-course dinners for $35.00 per person. Beverage, tax and gratuity aren't included.
Check out the list at this site:
Of the restaurants listed, my favorites are Mercer Kitchen (sit downstairs), Orsay, Vong, and Aquavit.
Normally, two people would never be able to get out of any of these places for under $100, so the promotion is really a bargain.