We love Silverado (we're wine club members there). They have fantastic cabs! If you want to splurge, their library tasting of older and reserve wines is fantastic.
We also really like Whitehall Lane and Conn Creek (members there too). Whitehall Lane has some great cabs and they do a really nice food pairing tasting upstairs in a private room. Conn Creek does a wine blending that is pretty incredible too - you get to blend your own wine from a dozen different cabs from various appellations in the valley. I learned so much in that session and had a lot of fun (their wines are great too).
They don't do cabs, but Prager Port works is really fun (need appointment) and Venge does an excellent tour and tasting (also appt only). And I have heard great things about Chappallet, Scribe, and Balducci (all need appt).
You didn't ask, but some general restaurant recs:
Redd and Bottega for a fancier dinner (I've not done FL but I think both of these have incredible food that's a more affordable alternative for a big night out)
Redd Wood - great pizza and pasta
Farmstead - really solid farm to table food. the burger is excellent
Goose and Gander - awesome cocktails
I'm in SF and head up to Napa and Sonoma about once a month so if you have any other questions, let me know.