Here are some cookbooks that I'm very curious about (all links go to US Amazon):
Baking
Artisan Bread in Five Minutes a Day: The Discovery That Revolutionizes Home Baking by Jeff Hertzber
Peter Reinhart's Whole Grain Breads: New Techniques, Extraordinary Flavor by Peter Reinhart
Booze Cakes: Confections Spiked With Spirits, Wine, and Beer by Krystina Castella
Regional Focus
From Mom With Love . . .: A Complete Guide to Indian Cooking and Entertaining by Pushpa Bhargava
Momofuku by David Chang
Experimental
Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods by Sandor Ellix Katz
Healthy and Vegetarian
The Moosewood Restaurant Cooking for Health
Modernist Cuisine
The Fat Duck Cookbook by Heston Blumenthal
Noma by
Ideas in Food: Great Recipes and Why They Work
Ad Hoc at Home by Thomas Keller