Might be a bit south for your distance requirements, but I'm a fan of taking out of towners to Salt Creek beach:
Metered parking, plus a big old park to hang out at and do some grilling. Walk down the hill and you're at the beach. If you have kids that need to be carried around, or old folks, might not be ideal. But I like it because there are never crowds, and mostly locals (except for the folks staying at the Ritz Carlton next door).