So many restaurants!
I see there have already been a few suggestions for a great Chicago restaurant, but I had to add another! My favorite restaurant of all time is Carmines. It has a variety of food on the menu, with mostly seafood, steaks, and pastas. A little on the pricey side, but it's worth it! Click the picture to view more pics and some reviews.
P.S. The calamari is to die for!