The following are restaurants that we liked on our recent trip:

Salamanca: 1. Restaurante La Aldea. We went here with my daughter's host family for dinner and we were a party of 6. Downstairs is a bar and a few tables - we ate upstairs in a larger room. We had an absolutley huge meal (delicious), with wine, for 75.
2. Trento Restaurante (1st floor of the hotel NH Palacio de Castellanos). This was a bit of an extravagance on Christmas Eve, but many restaurants were closed. The food was wonderful and the service great. (It's worth it just to look at the lobby of the hotel!)

Sevilla: 1. Bar Gonzalo (on Mateos Gago - a stone's throw from the Giralda) - a cute bar with eclectic oil paintings on the wall... check out the lady in the sardine can!... and great tapas. Especially yummy was a hot spinach dish with raisins. Calamari was good, too. Plenty of food for 2 - $15.00. Mateos Gago is a beautiful (orange) tree-lined street not to miss.
2. Pizzeria San Marco (on Meson del Moro), just up the street and around the corner from Bar Gonzalo. It has a fabulous interior, reminiscent of the Moorish influence, and a great Italian menu. The 2 of us went for dinner and had a generous portion of pasta, a huge jug of Sangria (oh, so good!) and a big bottle of mineral water for about $23, The atmosphere was lively and fun, without being obnoxious. It was crowded but we didn't feel rushed. A really fun place.
3. Restaurante Los Duendes (Sonteros #45), just outside the Alcazar. Again, we enjoyed a good lunch for 2 for $15.00. They had a pretty decent selection of paella - the one we got was delicious. The service was a bit slower than normal, but if you're not in a hurry, who cares.

Madrid: 1. El Caldero (Huertas, 15) - near Puerta del Sol. We ended up here for an early lunch on New Year's Day because so few places were open. The food was quite good, the desserts were incredible, and the atmosphere lively. On New Year's Day it was filled exclusively (except us, or course) with locals ... families celebrating the new year. Lunch for 2 was $38.00
2. Pan's and Co (a big chain of fast food) saved our lives for dinner on New Year's Eve/Day. Tasty, cheap, hot sandwiches and french fries with a spicy sauce.

In general I really liked the food, although I was surprised that it lacked spice. The tortilla became a mainstay for us: it was inexpensive, tasty, and readily available. We had good paella and calamari and most of the tapas were yummy. The bread, uniformly white, was scrumptious. If you get the chance, try "pistos"... a delicious blend of veggies, similar to ratatouille.
Advice: buy a cookbook!!!! good investment

"In general I really liked the food, although I was surprised that it lacked spice".
Compared with the much more famous Mexican cuisine the Spanish one lacks spice. I have wondered to myself why? and found the reason in wine. Spice doesn´t match with wine and being Spain the second wine region power in the world it is no hard to understand why spice may not be used, is it the same with the other wine powers (France and Italy)?

André