I HIGHLY recommend this place. The address is Espoz y Mina 6, and it is right around the corner from the Puerta del Sol--so it is very centrally located. It is within walking distance of a LOT of great eateries. I am not sure if this was a promotional thing or not, but we received vouchers for breakfast at a nearby taberna (toast with or without ham, cheese, and butter, and a cup of expresso).
You can walk to virtually anywhere, or take the Metro or a taxi to Atocha. If memory serves me correctly, the cab ride from Barajas Int'l was under 20 Euros. The staff is friendly, and the rooms are clean. Only minus--watch out on the way up the steps . . . the flights vary in height, and it can make for an embarrassing trip when going up or down! ;-) http://www.hostalalhambra.com/