Wine Country north of San Francisco

It's not all doom & gloom like older_fossil implies. And yes, I prefer the Paso Robles wineries, but that's just because I went to university there and it's sentimental. I have tons of great childhood memories from the Napa Valley as a kid too when my broke parents would drag us around wine tasting. It used to be free back then, so it was a great way to learn what you like. It was free too when my then-girlfriend-now-wife would go tasting in Paso Robles when we were students, which is how we learned what we liked.

There's absolutely nothing wrong with the Napa & Sonoma valleys, and the crowds shouldn't be that big of a deal. The cost for tasting can be high some places, but not prohibitive and you're on vacation so live a little.