I've found great recommendations here before - Txirimiri, Taberna Tempranillo, Casa Labra, Taberna Dolores, Casi en Huertas (closed?), Los Asturianos, but it seems like most recent discussion is about Barcelona and San Sebastian.
Any new and worthwhile tapas bars or restaurants? Has anyone been to StreetXo yet? Nikkei 225? El Oso? Sudestada? Punto MX? La Buena Vida? Casa Mundi? Bocaito? Rafa? Anything else from the past few years?
Rafa is still an excellent traditional seafood restaurant; they have a bar in front for tapas and raciones.
We had an outstanding meal at Lua in Chamberi a few months ago; they serve a choice of set meals but will inquire about any allergies or dislikes.
The 49e dinner we had there might have been the best value of any meal I've had in Spain in the past few years. Food was absolutely outstanding; small, handsome dining room; attentive and welcoming service. I am away from home so do not have my detailed notes but I give it my highest recommendation.
The food critic of ABC (one of Spain's leading newspapers) gave the following 2012 ranking of his preferred Madrid restaurants:
1. Santceloni (Hotel Hesperia)
3. Ramón Freixá
4. Nikkei 225
6. Kabuki Wellington (Wellington Hotel)
7. La Tasquita de Enfrente
8. Sergi Arola Gastro
9. La Terraza del Casino
Full article in Spanish: