I have to say it's a worthless list when Washington D.C. is on there. Who could possibly even claim that D.C. is better than Denver in any of the folowing categories:
climate, healthcare, crime rate, education and wealth?
http://en.wikipedia.org/wiki/United_..._by_Crime_Rate
http://www.infoplease.com/ipa/A0108505.html
http://www.infoplease.com/ipa/A0108620.html
D.C.'s per capita income is slightly higher, but I'll bet Denver's median income is higher than D.C.'s--as the latter is largely very poor with a lot of really rich dues. No one would ever voluntarily put their kids in D.C. public schools. The list is a farce.
It's interesting that, other than the four Japanese cities, the only two cities on the list that are not predominantly populated by whites are Singapore and Washington. And all six of the non-white cities are in the bottom 20 of that list.