I've only been to Chicago once. I found it really gray and drab. Went for a run every morning to the Navy pier. Road the L, visited my cousin, road it back at 10pm and didn't exactly feel safe (understatement). Went to the top of the John Hancock building to kill some time. Ate a great pizza, can't remember the place, but it was a really popular and really good deep dish pizza. Outside of that, I'd say one of the more interesting things I've read about Chicago is a guy by the name of Horatio Spafford. Won't go into details, but google it sometime.