Mine, having had a glass or two
Tom Keller: The French Laundry Cook Book. Read this and die of shame, anything you do in the kitchen will always be second best after this, but read it all the same. I take it to bed some nights, not to read, but just to hold. (Bouchon is as good, but not as original or cuddly, see below)
Anthony Bourdain: The Les Halles Cookbook. Good, solid French Bistro food, fun to read and easy to follow (if you don't mind the author calling you a dipsh#t.) Anyone can cook the recipes in this book, and they will work. Great book, and very impressive food that will scare your family and friends when you serve it.
Madhur Jaffrey: Indian Vegetarian Cookery. Cook better take-away food than the take-away, just learn how to do a bit of tandoori to serve on the side.
Joint fourth are HFW and Nigel Slater, both inspirational in their own way, but neither better than the other. Appetite and the River Cottage Cook Book are essential.
Elizabeth David, because I love her, and I wouldn't know anything if I hadn't read her first.
No-one else has stated a "don't buy", but I will:
DELIA SMITH.
Dull, recycled Marks-and-Spencer cooking for the numb-brained.