As someone who spends a lot of time in DC I'm not sure they have the best metro in the US. I personally like the NYC metro better for getting around the city. DC's metro is largely designed to get people into and out of the city during rush hour. Most people in the DC area don't use it for anything else and as a consequence it suffers from high ridership during rush hour and very little ridership at other times. Unlike NYC, there are few places you can live in DC without also owning a car.