Sauvignon Blanc is at its best defined in New Zealand, particularly Marlborough, and is still a long way off achieving a similar level of quality and consistency in its home location of the Loire Valley.  It is improving in Bordeaux, where it is also used in Sauternes and Barsac blends.  Some exciting wines have begun to emerge from the Cape winelands, South Africa (ignoring those that are artificially flavored), but California remains hugely disappointing, even though its vines are the same Sauvignon Blanc clone as New Zealand.

Info : The Sotheby's Wine Encyclopedia 4th Ed by Tom Stevenson