I don't want to come off as rude, but I ask myself "How many railroad sites with forums do I really need?"
Trains dot com was where I started out and was ok for awhile, but I lost my passion for it along the way, primarily due to the self importance and super inflated egos amongst their chief members in the only forum I really enjoyed - Trains Magazine.
Railroadforums dot com is a classy site with a lot of friendlies. I especially like the photo section on the front page.
Finally (I save the best for last) Railroad dot net is the one for me most frequented. I will continue to spend most of my time here.
There's more than enough knowledge (for little ol me) in just two websites alone. It's enough and don't know if I would have the time to take on any more. But I thank you for the info.