With a tip from a friend, I found a great wine store on Taraval Street in San Francisco that has some amazing stuff, mostly California (of course) but some French as well. They had decent prices on current releases but quite a cellar of older vintages, some at really great prices. I picked up a couple of Montelena Estate cabs from the mid-90's at prices quite a bit under what you'd pay at the boutiques up in Napa. Those were great. A 1989 (so-so year) Spottswoode cab that I picked up for a song was past its full-bodied prime but still drinkable, especially if you like the style of aged Bordeaux. Most recently of theirs, I had a '95 Dunn Vineyards Howell Mountain cab that was a little disappointing-- it seems to be in that cocoon phase that many middle-age California cabs go through.

K&L Wines, with 4 stores across California, also has some great old vintage stuff, also at good prices. They buy from collectors, estates, and from one-off releases by the wineries. I got from them a '92 Diamond Creek that was quite good, and a '90 Spottswoode that was really good.

I can give someone who's interested a more robust description of these, but that doesn't seem to be the point of this thread.