Most cookbooks I see are simply a collection of recipes. This doesn't interest me. There are so many online recipe databases that finding a potato soup recipe is trivial. Also, I find most recipes include the same basic ingredients so they are more or less the same.
To me an interesting cookbook presents a "way of thinking" rather than a random assortment of recipes that the author finds tasty. To put it another way, I'm interested in cookbooks that have a perspective. Also, they are almost always more "books about cooking" rather than "cookbooks".
Eric Ripert's "On The Line" is an example of an interesting book. Even though he includes some recipes (which I never plan to cook) I learned something because he discusses how the kitchen is organized and runs, the conceptual process of creating a dish, and food costs. David Chang's "Momofuku" is another example. I quite enjoyed the David's story of learning to cook in Japan as well as the failures, and eventually success, of his restaurants.
Here's a shocker -- I think Jacques Pepin's "Essential Pepin" is has rave reviews on Amazon, and that makes me want to buy it, but I think it's an awful book! The book's subtitle is "More Than 700 All-Time Favorites from My Life in Food". I can get thousands of recipes through Google, but what I can't get is Jacques wisdom and knowledge from "his life in food."
Cat Cora's "Cooking From The Hip" is an example of an awful book. The title implies that she would discuss improvisation, cooking without measurements, etc. Yet, when I opened it, I found the same tired recipes printed in other books. While Ripert's and Chang's books had personality and perspective, Cora's book was cookie cutter and boring.
Examples of other good books: Ratio, The Flavor Bible, Culinary Artistry, America's Test Kitchen books where they discuss the process of testing a recipe, Alton Brown, On Food and Cooking, etc.
Does anyone have suggestions?