We're big fans of Highway 1 and have had several good meals in Big Sur. Specifically at Nepenthe and Cafe Kevah (http://www.nepenthebigsur.com). Outdoor dining with a great ocean view is really hard to beat. It doesn't sound like your folks will be traveling along the coast but I figured it might still be worth mentioning. Also my wife and I will be taking a similar trip in November driving down the coastal highway from Portland to San Diego. I will be checking out the San Francisco thread that weinno mentioned and would appreciate any recommendations for north of San Francisco and Oregon. I'm especially interested in any sort of brewpubs in that route!
