Metra trains can be used to reach most hot spots. The Union Pacific West Line and the BNSF line are filled with hot spots, with heavy freight traffic sharing those lines with Metra trains.
Chicago's ten best train watching sites, as selected a number of years ago by TRAINS Magazine staff members.
This zoomable Google Map has been marked with the "Top Ten" railfan spots in the Chicago area. Also marked are the most useful public transportation transfer locations, for getting to and from these locations.