I'm a huge fan of Suzanne Goin's cookbooks, Sunday Suppers at Lucques and A.O.C. I feel like they're 2 of my secret weapons for entertaining and blowing people away with pure deliciousness.
Her food is loaded with flavor. She seasons her food at every step. She's not afraid to marinate a piece of meat and then dress it with two flavorful sauces. Yet, it never seems like excess. Her recipes work reliably for me. As a native of Southern California, I also appreciate her use of vegetables in preference to loads of starch.
Another reliable, fabulous cookbook that I love is Susan Spicer's Crescent City Cooking. She's based in New Orleans, so many of her flavors are based on the cuisine of that region. Like Suzanne Goin, she doesn't hold back on seasoning at every step and she builds flavor on top of flavor. The recipes in that book have never failed me; they range from outstanding to very good and are usually outstanding.
Those two chefs/authors are similar, in a way. So whom else would like? (I have nearly 300 cookbooks already; I'm not a newbie.)