For me, this is impossible to declare...my foodie life has gone through stages
Young married couple, and then kids, then kids go away, now we are two again and retired. I had my favorite cookbooks with each cycle. The red and white plaid of Better Homes and Gardens was my first and I have many faves in that one. Sunset cookbooks became a fave when raising the kids, then I went through the gourmet stage, and have many cookbooks from great wineries, and small cookbooks from Junior League of Palo Alto, or another from Mamie and Ike Eisenhower, Cookbooks from hospital volunteers, and great chefs, all have special recipes for me. I published a cookbook when working for Redding Police Dept. All recipes from the officers, support staff, even the K-9's and kids contributed! Great stuff in there.
Now I have three massive binders full of tried and true recipes from sites like this, favorite bloggers, and TV cooking shows. More and more I am looking for fast, easy, yet excellent and healthy recipes using in-season ingredients. So, you see, I cannot name any top ten cookbooks. Last winter I cooked from Jerusalem, The Portuguese Table, Ina Garten, old favorites from long ago, many new recipes, and so much more. So many recipes to try and such a short time left to do it. Do angels in heaven cook? I sure hope so...