I live in Podunk, USA, where there is no public transportation. I have become amazed, awed, impressed with the trams and trains in the Netherlands, and the trains in Italy. They are usually clean, reasonably comfy, efficient, ON TIME, and affordable. Plus, if you're lucky, you can visit with the locals, even across language barriers.
The fantastic public transit systems found throughout the continent is one of the main reasons I travel to Europe as much as I do. When I go to Europe not only am I taking a vacation from work, I'm taking a vacation from my car!
Some reasons for the European public transportation being so good:
1) Lots of people in very short distances. Put a map of any country on most of our states, then compare populations.
2) High car prices and gas prices due to taxes. No easy parking even in relatively small cities.
3) Love of the car never took off as it did in the U.S.
4) Government subsidized train service. Mostly national railroads vs. traditional privatized U.S. ones that decided to drop service years ago.