Alright, so we're all familiar with the usual touristy rubbish that passes for city tours. The guides typically don't know anything, the buses don't go anywhere interesting, and ultimately you could have seen more yourself by walking. The Chicago Architecture Foundation, by contrast, specializes in narrated walking and riverboat tours of the downtown area of Chicago that points out interesting highlights in the development of Chicago as a city. Their tours are a little more expensive than the more touristy ones, true, but hopefully you will get more out of it. I highly recommend the river tour.
If you don't want to know all about the history of Chicago architecture, however, you can try the cheaper river tours offered by their competitors. The view is the same, the only difference is the narration.