Just got back from Spain and Portugal (22 days). In Madrid, we stayed at the Aparthotel Eraso
. The weekend rate (Fri, Sat, Sunday) is 63 Euros and the weekday rate is 96. Very nice place. Very clean. All floors are in marble. We stayed there twice (beginning and end of our trip). On our last stay, we had a room that was the size of 2 hotel rooms (about 400 sq. ft.) It had a kitchen area (fridge, stove top, cabinets, microwave oven, sink), a dining table, a sitting area (hideabed sofa). Downstairs, right next to the hotel is a restaurant/cafe where you can have breakfast, lunch and dinner. There are several set menus for lunch and dinner costing between 6 to 8 euros (2 course meal that includes bread, drink and dessert). The subway (Diego de Leon) is only a short street block away in Francisco Silvela(very convenient). Just within 100 feet of the subway entrance are cafes, restaurants (including Macdonald's and Burger King), a fair sized supermarket where you can get nearly everything, pastry and bread shops.
The hotel caters mainly for families (who can cook in the apartment) and business people. Security is good (there is a direct link to the police station) and the front doors can be locked in an emergency. It is located in the Salamanca area which is an upscale residential area.
The close location of the subway makes it an excellent choice (3 star hotel). The subway is also a link for lines 4, 5 and 6.