Deciding last minute to stay in Madrid Spain for 2 nights, 3 days and we are looking for a reasonable, clean hotel where we can tour the city, don't mind if the hotel is further out as long as it is within walking distance of public transportation. Thanks

Two we like are the Room Mate Alicia and Hostal Persal about 1/2 block from one another and extremely convenient for seeing Madrid.

What is your budget?

That is a pretty open-ended inquiry that would describe hundreds of hotels. I like the Intur Palacio San Martin.

You'll want to stay as centrally located as possible to save travel time, unless you don't mind commuting by metro or city bus.

As danon noted, a budget would be helpful in pointing you in the right direction. What's reasonable to some may not be reasonable to you.

Budget $150-$160 per night. I usually get a HotRate for the Starwoods Hotels but I can't get into the Westin or Sheraton in Madrid, they are all booked.

NOt sure how "last minute" but I got a great rate at one of the Marriott hotels for next week. They seem to be having some good sales.

I have stayed at the Hotel Europa in the past and it was well within your budget, good location and clean. Great location

You can find a number of four star hotels in the centre within your price range.
Check booking.com close to Plaza Mayor.

What sort of dollars are you writing about?
PS we use Euros here ;-)
Go with Danon's suggestion it works the best.

If you're on a budget, then Hotel Principe Pio just off Plaza d'Espanya and opposite the Sabatini Gardens next to the Palacio Royale might fit the bill.

Close enough to the centre to walk in, but also great bus connections too.

I use to stay in great value Hotel Plaza Mayor or Persal (mentioned above) in the heart of the city, between majestic Plaza Mayor and vibrant Plaza Santa Ana. Both will meet your budget.

Hotel Plaza Mayor: http://www.booking.com/hotel/es/plaza-mayor.html
Hostal Persal (all hotel amenities, excellent place and very popular): http://www.booking.com/hotel/es/persalmadrid.html

The area:
Plaza Mayor: http://www.gomadrid.com/sights/plaza-mayor.html
Plaza Santa Ana: http://www.gomadrid.com/sights/plaza-santa-ana.html

I use booking.com to see if their price is better/worse than the price quoted by the hotel site.You'd be surprised how it varies! Just be careful when it come to the cancellation policy in both cases.