DKM et al, see http://www.pizzamaking.com/forum/index.php/topic,12256.0.html
for a link to a story on the variety of pizzas in Chicago. Lots of great places, not just the "Chicago style" we hear so much about. They make so much more there!
Back when I lived there, on Broadway (or was it Clark or Halsted?) there was a little Nancy's pizza place. Real small, maybe twenty feet wide for a storefront, probably less -- they had slices of spinach stuffed pizza to go. It was my first exposure to stuffed pizza, and I loved it. It hooked me. Today, Nancy's website claims it invented the stuffed pie. I urge you to check it out and see if it's still there -- a block toward the lake from the Century Mall.
Growing up there, I tried stuffed pies all over the city. I once had a great pie in Bellwood at Gioacchino's, but Edwardo's was good, as was Bacino's, and Giordano's in Hyde park. In short, too much great pizza, not enough lifetimes to eat it all -- in Chicago alone. I urge you to explore, explore, explore!
Lots of great thin in Chicago as well (even lots of wood-fired oven pie places are popping up.) As for "Chicago thin," I heard Aurelios in Homewood is legendary, decades old. I also like Connie's thin, too, though it really isn't anything special. It just hits the spot. Carmen's in Evanston is (was?) OK as well, but for stuffed.
And of course, pan pizza at Lou Malnati's in Lincolnwood -- THAT'S the specific Malnati's to go to. As to Uno and Due, compared to the other pies out there, IMHO, I think much ado about nothing describes them well. Heck, the old "My Pie" (picture the "pi" symbol for the number 3.14...) on Clark (but sob sob now gone!) used to better Uno's or Due's as I recall.
But it's all a matter of preference. Try it all -- lots of grea pizza of all kinds!
And don't forget Chicago dogs! Next time you're there, get Chicago's own Vienna hot dogs -- Superdawg is a MUST stop-at.