I love Chicago deep dish, but it's not pizza. It's a casserole. The only good casserole on earth. Lou Malnati's is the best for me. There's one coming to Indy and I'm pumped!
NY style with the big, thin slices is great as well. There's a guy from Sicily that somehow ended up opening an amazing restaurant next to the small town I grew up in. His wife took him from Sicily to North Salem, IN, a piss ant sized town of 508 people. His pizza is superb and is the closest thing I've had to the real deal NY style outside of NY.