Maybe it will help if you define what "late night" means to you. In addition to the Food Court shops at 500 W. Madison St. there are the restaurants locatted inside Presidential Towers to choose from - a Thai place, La Margarita, an Italian place, McDonalds and the Deli counter at the food market in the complex (a great place to buy lunch, by the way). There are also some places on Wacker Drive, and, of course, the places a short walk away at Randolph/Halsted or in Greektown.