The USA isn't the envy of the world for anything these days. Only Americans think that. Nobody envies you for anything, not even Silicon Valley, with the housing crisis and poverty surrounding it.
http://business.time.com/2012/07/09/us-freight-railroads/ - "US Freight Railroads are the Envy of the World"
But if you don't trust the Americans let's ask the Brits.
http://www.economist.com/node/16636101 (The Economist) - "America’s system of rail freight is the world’s best" and "They are universally recognized in the industry as the best in the world."
It's a fact generally acknowledged. I'd find you more variety but it's harder to get detailed Asian and European perspectives in English, you know?
That said, I sure hope no one envies Silicon Valley. An individual facet of it like the jobs or the climate, maybe...
As for the best of the best, I just kinda think Deutsche Bahn has us beat. And Japan. And Switzerland ...