Working at the East Troy Trolley Museum. I found a love for the south shore steel side rail cars.
These are really nice cars to work on (first hand experience) and would make interesting models.
The other cars that I love are L-8 center cab, work car D-23 and crane car L-6.
http://easttroyrr.org/roster/13.html
http://easttroyrr.org/roster/l6.html
http://easttroyrr.org/photos/Cars/Line%20Car%20D-23/index.html#IMG_0978.JPG