I really enjoy railfanning at Bush St in Baltimore, especially in the evenings. The light is perfect for westbound trains, and having the city’s skyline in the background doesn’t hurt either. Also, the traffic is pretty steady and interesting, and you never know what other railfans you’ll run into.
One of the below photos even got accepted to Railpictures.net, which many photographers will know, is an accomplishment (or just dumb luck). See http://www.railpictures.net/viewphoto.php?id=481378