The Rutherford AVA.

Right above the Oakville AVA (the AVA in which I work), is the Rutherford AVA.  Named after Thomas Rutherford who, upon marrying George C. Yount's daughter, was given 1,000 acres of land from his new father-in-law as a wedding present, Rutherford is/was the home of at least two of Napa's most historic wineries - Beaulieu Vineyard and Inglenook (whilst under the ownership of the visionary John Daniel Jr., not Francis Ford Coppola).  Nowadays, the AVA is the home of many renowned wineries e.g., Caymus Vineyards, Frog's Leap Winery, Mumm Cuvee Napa and, for all the wrong reasons, the nightmarish, to me at least, Raymond Vineyards.
Rutherford is perhaps best known for its soil, in fact the soil even has a society named after it: the aptly named Rutherford Dust Society.  André Tchelistcheff, who is credited with introducing modern winemaking practices to the Napa Valley (whilst at Beaulieu), said, "It takes Rutherford dust to grow great Cabernet."  Hmmm, I think the folks in the other AVAs would likely disagree.  The fact is, the entire Napa Valley is unique due to the diversity of the soils found here.  I personally can't really claim that I have ever tasted dust in any Rutherford wine I have tried, but I'll continue to experiment.  It's a tough job, but somebody's got to do it.
Five down, eleven to go.