Blackbird has a 3-course prix-fixe lunch for $22 Monday through Friday that has never disappointed. Blackbird is in the West Loop, but I've never had a problem finding parking, and it's not too far from various public transportation options.
Blackbird
619 W. Randolph
Chicago
312-715-0708
Anthony Bourdain on Barack Obama: "He's from Chicago, so he knows what good food is."