La Cova Fumada

This is some of the best food you can find in Barcelona, period. La Cova Fumada is in Barceloneta, situated among many other tiny, signless places. Their claim to fame is that they invented the bomba (a potato "bomb"), so get one of those, as well as the tiny tallerines, which could best be describe as “clams for ants.” They are so, so good. Note that they have wacky hours, as most tapas places do, so make sure you check first.