Napa is our FAVORITE place, I highly recommend "Jarvis Winery" its actually built into a cave, with a natural spring and waterfall inside, absolutely stunning! You do need reservations and its about $30.00 per person, but worth every dime, the wine tasting room is beautiful, the food paring is fabulous, your not rushed. Its a definite "do not miss"! Oh, and yes the wines are excellent! Another plus, they donot push you to buy anything!
Over in Sonoma, not far at all, is Ledson Winery, its a huge beautiful castle, the grounds are perfect for a picnic and bottle of wine, and wine tasting rooms in the castle are breathtaking and the wines are terrific, as are the people that work there.
These are definitely "YOUR MUST SEE" wineries, you will have beautiful grounds, absolute knowledgeable, outgoing, personable people interacting with you, and the wines are excellent!
Sip, Swirl and Savor!