I was just out in Chicago again over the summer. Had only 1.5 - 2 hour layover before my train connection to California. ..So only did one thing... went to Giordano's for deep dish pizza & beer. Made the extremely short time there worthwhile.

From my first time out there 9 years ago.. the only other suggestions I can give you off of what I remember are the obvious touristy landmarks like Sears Tower & John Hancock Building.

Oh, & if memory serves right.. I think there's a architecture museum.. could even be more than 1.. knowing Chicago being famous for it's architecture.

Maybe roam Greektown.. I think that's where I was based in 2000.

Chicago's known for it's Polish people.. so maybe have Polish food.

I think Chicago also had a cool looking library interior.

Go over to look at the Great Lake obviously.