I just got back too... Madrid was so wonderful! Too short of a trip! We stayed at the Hotel Europa in Puerta Del Sol, which was a really nice place albeit 65E a night, and then at Grand Duque over by the Opera Metro stop. It was 50E a night, very clean, nice, a little noisy (neighbors). I had the feeling you could get roughly the same for less money.

What a town, can't wait to go back

And yes, this web site was immensely helpful... although I must say Madrid is a very 'easy' city to enjoy!