Los Amigos Opera Backpackers Hostel

Small hostel located in the center of Madrid and within half a block of a metro stop. It's on the 4th floor (5th in American-speak), but there is an elevator ("lift" in Brittish-speak). There is a common area with TV, bar, and kitchen. Male and female dorms are segregated to separate wings of the floor. The bathroom facilities are good and the staff is friendly. Extra €5 "day fee" if you want to stick around after your checkout time.