Dessert Wine in Sonoma?
Ferrari Carano's Eldorado Gold, Williams Selyem Muscat Canelli and Late-Harvest Johannisburg Riesling, numerous Rieslings by Arrowood (as mentioned), Ridge Late Harvest Zin, Bella Late Harvest Zin ***, Chateau St. Jean -- several late-harvest Rieslings.
Trentadue Zinfandel Port ***, St. Francis
I'm not sure if you're talking about visiting Sonoma County wine country more generally, or the Sonoma Valley AVA specifically, but...we liked Dashe's 2007 and 2008 Late Harvest Zins. The grapes for these wines came from the Dry Creek Valley AVA, in which the (cheesy) tasting
room they share with some other wineries is located.
Dashe's current offerings:
Sonoma tasting room information:
I like the Moscato at Jacuzzi.
As it's large and free to taste, it can get crowded on weekends, but it's pretty well-staffed, and I've always had an enjoyable experience there.
Of course, the drive up to Praeger Port in Napa/St. Helena is totally worth it and the $15 tasting fee.
Picked up a bottle of late harvest Sauv Blanc from Merry Edwards for $39 over Thanksgiving weekend that was very tasty. It was more of a pet project for them, Merry decided last minute to keep a couple acres in 2008 as a late harvest so there is not a large quantity of it. They did not bring it out as part of a standard tasting but we saw it on the bottle list and requested a taste.
Full disclosure: I know VERY little about dessert wines - I typically only drink them at restaurants once a month or so but I liked this one enough to have this be my first dessert wine purchase and it could be a more unique dessert wine to give as a gift due to the small quantity.