Go for the menu del dia (menu of the day).
It is by far the best option financially and you usually get a simple, but perfectly balanced 3 course meal, with wine and coffee, for under 10 Euros.
Mind you, who knows what is on the menu...Especially if the menu is hand written in CataLan !
In my experience, it is best to go for a family owned restaurant, with simple , traditional decor. Although it can be a little confusing to those not used to the region/language, it is worth it.
We had hired a car, so we took the scenic route to nearby Tossa de Mar for lunch on recommendation from close friends who lived there.
We had a really good, quality meal there in a traditional restaurant with interesting decor, that specialized in seafood. There are restaurants lining the streets leading up to the old town. We pushed the boat out and had three courses, wine and coffees etc, and the price was unbelievably reasonable.
As always, small peole are treated very respectfully in Spain.
I cannot remember the name of the restaurant, (It may have been Es Moli) but most are good along that strip, just look for the most tradional looking one on the right, near the bottom of the hill. (you can see the decor style in the pic).
Very good quality, highly recommended.
Favorite Dish: The Small Person loves mussels, these were especially good here.
The wine was also good.
Cantina Mariachi is a very good Mexican restaurant. Tasty food, good service, nice hall, outdoor terrace - everything you need. One of the good points - they serve a very tasty sangria, another one - they have big dishes, made especially to share between family or friends.
Favorite Dish: Nachos Machos! :)
It is a big plate of nachos (to share it) with a very tasty sauce. Can be a good late dinner for two women. ;)