Couldn't resist popping in to recommend Txacolin in Barcelona. It's a fantastic place for pinxos (small plates) and Basque cider. Get there early (9:30ish) as it fills up almost every night. There are cold pinxos within reach, but the real treasure are the hot plates which come out of the kitchen every few minutes. Your patience will reward you, especially if a few ducks got the ax in the back room.
For around 30 Euros you can have a fantastic dinner. Location: Marques de l'Argtentera 19 in the Born across from the old train station.