San Luis County Regional Airport

Was there very late at night, and even though they were closing up all the staff was very friendly and helpful

A nice towered airport that's an almost perfect fuel / food / exercise break for GA flights between the San Francisco Bay Area and the LA area. You can get pretty good American Diner fare at the airport cafe, the Spirit Of San Luis (breakfast, lunch, and dinner), and there are scheduled commuter airline connections from here to the usual LA, SF, and Central Valley destinations. The area itself is growing rapdily and getting something of a name as a new wine country destination. Note that like most of coastal California, the coastal stratus can come in quickly in the evenings, so if you're flying VFR, keep a good eye out for the weather.