The largest city in Galicia offers the best seafood worldwide. Try the restaurants located at the old part of the city called "La Piedra". P.S. Eating good is not cheap, but definitively worthy.
I liked the beautiful clean beaches, the going out scene, the cheap prices for taxis, shops and bars. The combination of the beautiful green mountains, white beaches and nearby cities (Santiago de Compostella and Pontevedra) make it an excellent holiday spot. Nobody speaks English here, so better be well-prepared or bring your little phrasebook ...