Had a really nice stay at Duo Housing DC. The location is really good and you can reach all sights walking. Even if there is no free parking in front of the hostel there is a parking lot near by where you can leaf your car for $ 12 a day. Or if you are lucky like I was you can park it for free three blocks down the road. This tip I got from the really friendly and helpfull stuff. They also made really helpfull recommendation what you have to see in the city and where to get good food.