I would like to see Subway routes from New York (MTA), Japan, NY/NJ Path train, Chicago L, etc. Hoping this will one day come to pass.
That would be cool but having been on all of those lines you mentioned it might be many miles for them to include. I with they would eventually be included as well but it seems realistically as if any of those are prob years away. The easies to accomplish would be for the path train since they already have some of the line included for the Northeast Corridor and Harrison station is already there even if you can't stop at it.
Hopefully they read the forums and will take it into consideration. I would love to see them add the Odakyu Odawara line from Tokyo to Odawara or the Meguro/Mita line which isn't too different from the Rapid Transit stuff already in the game with half of the line being outdoors and half being underground.
DTG have already said that they don't like doing too much "underground" stuff but given they have a rapid transit line on TSW already, maybe they will do more if it's pretty enough
I can understand that since there's not much to see underground. I'd like to see more rapid transit routes and trains though. Maybe this is only the beginning.