We were using Penelope Casas' "Tapas: the Little Dishes of Spain" on the weekend and I noticed that at the back of it she has a list of favourite tapas bars by city across Spain, and also in some of the larger U.S. cities. The book was published in 1985 (I checked on the "All Spain Market," MM!) so perhaps many of them (especially in the U.S.) don't exist any more, but you never know.