Modernist Cuisine: The Art and Science of Cooking sets a new paradigm for cookbook encyclopedias.  With stunning photography and throughly detailed scientific explanations of cooking techniques and methods, this extraordinary boxed set is informative and enlightening.  Many of the recipes are more like science projects, requiring esoteric equipment like centrifuges that few home cooks are likely to ever encounter.  But anyone with a keen interest in the avant garde techniques of today's most innovative chefs will find the series mesmirizing.  The first edition quickly sold out (and is available for resale at huge markups from it's already hefty price), but you can get in line now for future print runs. About $500 from Amazon.com.