Clos Pegase is a fun winery to visit. It's near the CIA. Hess, is out of the way, but worth the trip if you have time. They have a little art gallery at the winery. Opus is a must see. Keep in mind the tasting fee is pretty stiff there. Mondavi has an in-depth tour and tasting experience. Requires reservations. Arrowood in Sonoma is also very nice. Enjoy yourself!