I definitely recommend Hostal Plaza D'ort ( www.plazadort.com/docs/english.html
). It's right next to Plaza Santa Ana (out the door to the right) and a minute or less walk to Puerta del Sol (out the door and straight ahead). It was clean, the people were really nice, and there's 24-hour access. I stayed there for 5 nights in October and will stay there again if I make it back to Madrid. I paid 4900 per night for a single with a complete bath (w/shower).
You can request a reservation in English via email and you'll get a quick response - in English.
[ 01-23-2002: Message edited by: MadridMan ]