I stayed in the suburb of leganes on the hotel Avenida, 8 min walk to the bus which will get you to CW in maybe 20 min- bear in mind that you are in the suburbs and the city center is far away- It looks fancier on
http://www.cadenahotelavenida.com/ than it is but its fine, clean and new and shops and bars, restaurents are close. there must be countless hotels in the area, but let me know if you diig up anything cheaper and better.