Bonny Doon is a favorite of mine also, both on price and taste (they are local). There are also two other little local places that have a nice dessert wines too; One is from
http://www.chouinard.com/ who have a number of unusual wines such as the Granny Smith apple wine. Excellent Muscat and Sparkling wines, as well as a good selection of good, inexpensive reds. The other is one is called Nebia (formerly Obester) of Half Moon Bay and it comes in a very cool half moon bottle (will take pics). They also have something I had never had before, a Black Muscat, which is a deep red Muscat that is sweet, but tastes a little different than a typical one. It is almost like a light port.