"Ranked according to what?" you ask.
Why, sustainability, of course. And according to SustainLane.com, the most sustainable American city is Portland, Oregon. (The next four cities this year were San Francisco, Seattle, Chicago, and New York.) Portland's top spot isn't a big surprise since the city has topped this list since it was invented in 2005.
Sustainability can be a slippery word to define, so SustainLane's methodology is here. And a lively debate over how relevant and accurate these rankings are can be found here. But you won't find many Portlanders engaging in petty bickering about our exalted status. We're too busy pedaling past xeriscaped front yards on our way to the community garden.