Assuming you have transportation worked out, and assuming you are French/Francophile, let me make a couple suggestions:
French - two suggestions for cheap, good French:
Le Bouchon, 1958 North Damen, cheap, authentic Provencal French
Rudi's, 2424 North Ashland Ave.
Vietnamese - Pasteur, 5525 North Broadway - one of the BEST cheap restaurants in Chicago
Algerian - The Casbah Cafe, 3151 North Broadway.
Moroccan - L'Olive, 1629 North Halsted, at North Avenue
Pizza - Lou Malnati's (best "Chicago-style" pizza in Chicago)
Mexican - Caminos de Michoacan #2, 3948 North Sheridan - SO good, authentic and dirt cheap!
Un peu plus cher:
American - Jack's, at Belmont/Halsted; great California wines and beef tenderloin. HUGE desserts.
Enjoy your stay there!