I think I like the sound of Spain.
Forget the prudish Catholic bit. The Spanish are a relatively live-and-let-live bunch and attitudes are surprisingly relaxed. In fact, the laws regarding public nudity are the most liberal in Europe and right to dress (or not) as you see fit is enshrined in the Spanish constitution.
Theoretically, you can be naked on any beach, or indeed in any public place. In practice, most people wanting an all-over tan stick to either official naturist beaches, or beaches where there is a tradition of nude sunbathing.