I am a huge advocate of mass transit, to the extent that I don't yet have a driver's license (I've had a permit for well over a year, but I haven't yet had the time or need for a license, nor can I afford to buy a car or pay for the insurance).
Anyway, I love mass transit, especially rail transit. In the past year, I've ridden MARTA (Atlanta), NJ Transit on the Northeast Corridor (New Jersey), Newark City Rail(Newark, NJ), PATH (NY/NJ Port Authority), MTA (New York), Subte (Buenos Aires), Hudson-Bergen Light Rail (right now only Hudson County, NJ), Metro (Washington, DC), the El (Chicago) and of course Amtrak.
The Subte in Buenos Aires stood out from all of them. First of all, it cost 70 centavos (about 20 cents American at the time) to ride anywhere. Second of all, it was jam-packed as tightly as possible with people during times even close to rush hour. I mean jam-packed tightly! Granted, Buenos Aires is far, far more densely populated than most American cities (this was clear when comparing the overhead nighttime view of Buenos Aires [tightly packed going quickly to rural in terms of lighting] to that of Houston [godforsaken sprawl from hell].
Anyway, there's some good news in the transit world:
The #7 line on the MTA is being extended to 10th Avenue by Hudson Yards (granted, the subway already goes within about a half mile of just about everywhere on Manhattan Island, still, it could be a quarter).
Phoenix's light rail system is beginning to be tested in traffic and will hopefully soon be in operation [hopefully with expansion].