I'll give the America's Test Kitchen Family Cookbook my vote. Full of great recipes and really helpful, practical advice.

Though not a cookbook, the book Heat by Bill Buford is also a good read and gives some insights and tips from the perspective of a guy who transforms from journalist to culinary apprentice. The last 1/4 or so of the book was kind of dull to me, but the first 3/4 was pretty riveting considering the subject matter.