Chicago resident chiming in here.
The pizza place you are looking for is Lou Malnati's, they have a chain in the Chicago area. Many people will try to steer you to Uno's, Giordanos, or Connie's. These people are ass hats.
Lou Malnati's is, hands down, the BEST PIZZA IN THE UNITED STATES.
Order an extra large butter crust sausage, cook it at high heat (425) until the crust is crispy and only cut slices as you plan to eat them. This will preserve the texture and let you save most of the pizza. I am a BIG eater and I can only handle two slices per sitting. It's an outstanding pizza. The sausages comes as one HUGE patty that covers the pie.
If you don't like the pizza, I will come to your house and bludgeon you with remnants of said pizza. You will spend several months in traction.
Put it this way - this is the place I take my friends from out of town when they ask for "The best food Chicago has to offer". When I go home to Chicago, the first place I order from is Lou Malnati's, (but I can't forget Portillos, Tore and Lukes, Buffalo Joes, Sarki's, Charlie Trotters, and Wildfire).
www.loutogo.com
Chicago is the best food city in the country.