Where's the option for both?
My local community has a tennis association, so it's a little bit like a club, but not quite. Basically you pay a small annual fee to get access to the courts and help to pay for court upkeep. They run several tournaments every year and do a tennis ladder and a non-USTA team tennis league. The Tennis Assoc. also holds fun mixers and a very fun drop-in-tennis night.
I play both local and USTA tournaments, but even when I have a ladder match, odds are it's against one of my friends or a person I know. On the flip side of that, a lot of the people I play against competitively also get together and hit around for fun.