Try Ferragudo, went there last year and its very low key, the old part of the town is lovely, all narrow streets, and in the main square they have entertainment on saturday nights which is put on for the townspeople although tourists are welcome too, when we went it seemed like the whole town had turned out, from toddlers to grannies!
There are a few bars, very friendly, and the only downside is that from the beach on the estuary you get a "lovely!" view of the huge high rise resort of Praia de Rocha on the other side, but if you stick to the other beach you can avoid that.