I'd recommend one of these 3, if you're looking for the "best" (in my opinion). Also, if you need some winery suggestions, happy to oblige. Per Jim's point, Napa will tend to be snobbier than Sonoma... but if you know where to look, there are a ton of great, small-production wineries where you can get some great 1-1 attention, and some even better wine.
Bardessono in Yountville
http://bardessono.com/
Auberge Du Soleil
https://aubergedusoleil.aubergeresorts.com/
Meadowood (which is also home to the 3-michelin star restaurant, the Restaurant at Meadowood)
http://www.meadowood.com/
Other people would also include the Carneros Resort, and Calistoga Ranch.