7. Washington, D.C.
If D.C. residents managed to score a place in Dupont Circle, Logan Circle, Downtown, Foggy Bottom, Mount Vernon Square or the U Street Corridor, just about everything they could ask for is within walking distance.
The neighborhoods get a big assist from D.C.'s Metro, which handled 409 million riders on its buses and subways last year and takes a lot of the traffic and tourists off the road to Reagan International by bringing them there directly. The city's park space and long streets and blocks meant to draw people into its center make it pedestrian-friendly by design, even if the original blueprints didn't call for high-speed vehicles and intersections that require good sneakers, stamina and a sense of one's mortality.
That's great for Georgetown, Friendship Heights and Chevy Chase residents, whose neighborhoods are kind to the car free, but 20% of the city still needs a car to get around and there are tourists who've been trapped in the city's maze of roads since Jon Stewart and Stephen Colbert's Rally to Restore Sanity and/or Fear. Convenience is all a matter of perspective, if not ZIP code.