Chicago Boat Tours

I've been hearing a lot about all the boat tours in Chicago. Could you guys help me pick one out, there seems to be a few operators. I found the following websites: http://www.chicagoline.com/ http://www.chicagotours.us/tours/tou...l.cfm/tid/1355 http://www.cruisechicago.com/ I also notice that there are River vs Lake tours, Historical vs. Architectural tours, etc. Any tips would be appreciated, thanks!>