Hi everybody, just wanted to share some feedback on my hotel experiences.
(Keep in mind when I first planned my trip it was to stay with a friend near Guadalajara, so the two hotel choices I made were rather last-minute and hasty.) Hotel Regina
has an excellent location - Calle Alcala 21 - near Puerta del Sol. If you love to walk like I do you'd never have to take a cab, bus or metro anywhere. It's a three star hotel, clean, comfortable, pretty ... but a single room was 72 euros (ouch for a solo traveler) and later the following week I got a room at the Hotel Mora for 50, which was much more of a bargain. (One perk about the Regina, a huge internet cafe and VIPS right next door - great to have breakfast and check your email in the morning.)
Hotel Mora is near the Prado museum, Reina Sofia, and the Atocha station, not to mention El Brillante (calamari sandwich heaven). The single room only slightly smaller than the one at the Regina (couldn't do many yoga poses in either room without hitting a piece of furniture or a wall!), and while less swanky and very no-frills, it met all my needs - bed, safe, bathroom, phone and window to the exterior. I didn't need a TV or A/C, but they were also also available. The Mora has a cafeteria downstairs, which is also very convenient. Since I was traveling alone, I wanted to stay in a hotel that had a well-lighted entrance on a busy street and that was more family-oriented. The Mora was also quieter than the Regina. Both windows faced the back streets, but at the Regina there were some folks carrying on with their Botellon (outdoor street party) long into the night. It didn't really keep me awake (I was too tired from all my walking), but it would've been annoying otherwise.
I saw some of the double rooms when they were open for cleaning and they were surprisingly spacious!