David Thompson: Thai Food
I've looked at lots of Thai cook books, and this is the one. Comprehensive, beautiful, and intelligently written.
Fuchsia Dunlop: Land of Plenty: A Treasury of Authentic Sichuan Cooking
Wish I'd had this book 20 years ago.
Bruce Cost: Asian Ingredients : A Guide to the Foodstuffs of China, Japan, Korea, Thailand and Vietnam
A classic reference.
Michael Ruhlman: Charcuterie: The Craft of Salting, Smoking, and Curing
Charcuterie is French for 'God's work.'