What's the best camping club to join?

I already have a membership in Good Sam. I want to drive around the western USA (mostly) and camp in nice clean safe campgrounds with either tent camping or camping cabins (where you bring a sleeping bag and stay in a plain cabin).

All I know about is 1000 Trails and I don't know much about that club, just heard of it.

Are memberships you buy from a member any good? Would I save money buying a membership that way? What about what they call "enhancements?

Any information about this would be appreciated.