i second Fernandos. Nothing fancy...but good arroz con pollo...and the camarones are really good (pay slightly more to get the larger ones).
the restaurant in the middle of town serves decent food. and there is always pica pollo and the chinese place if you are really on a tight budget.
DONT eat on the beach. you will be way over charged.
There is also a good place right by don amilio (sp?) that was really good. Great seafood...no atmosphere but good stuff at great prices..thats where the folks from santo domingo go.
if you really want to splurge for something fancy and dont mind the price...the of course there is Neptunos.
there is the "blue" restaurant on duarte...I forget the name...its ok but over priced for what they serve. Fernando's is better.
I am lucky...my friend cooks pulpo creole, lambi, and pescado en leche de coco con arroz y maize, tostones and so many other things. home cooking is the best!!!
Oh...i think fernandos is closed on either monday or tuesday (i think tuesday). Like BB said...nothing fancy but good and decent and local food at a very good price.