Here is the premium list:
Sancerre and Pouilly-Fumé: These villages faces each other in the Loire. These wines are usually more retrained than Sauvignon from New Zealand, but still have varietal green fruit and herbaceous notes, with a hint of smokiness.
Bordeaux: Most premium white Bordeaux is a blend of Sémillon (dominate) and Sauvignon Blanc, allowing complexity to develop with aging. It's hard to describe the flavours in a couple sentense, but it definitely show cases the best characters from the two grape varieties beautifully. The best Bordeaux comes from Cur Classé châteaux in the Pessac-Léognan and Graves AC.
New Zealand: In my opinion, New Zealand's Sauvginon Blanc is the best in terms of quality and value. The classic style is dry, high acidity, no oak, medium-bodied with distinctive, intense, pungent, clean, green varietal flavours (asparagus, pea, passion fruit). Look for wines from Marlborough. Cloudy Bay is my favourite.
Chile: I find myself buying more and more Chilean wines lately. You will find good quality Sauvignon Blanc at half the price compared to Sancerre. Casablanca would be the best region.
California: Due to the hot weather, only buy Fumé Blanc, oaked Sauvignon Blanc, from California. Usually, these wines have spicy, oaky flavours. Napa Valley is the best region.