My favorite is probably The Botany of Desire by Michael Pollan. It's not as popular as In Defense of Food or The Omnivore's Dilemma, but it's an interesting series of "case studies." Each of the four chapters examines how human desires affected the evolution of a particular plant: the apple for sweetness, the tulip for beauty, marijuana for pleasure, and the potato for sustenance.
I've also recently read Recipe for a Perfect Marriage, a story about a food writer unsure of her recent marriage, intertwined with her Irish grandmother's story and seemingly stable marriage.
Anything food-related on your summer reading list? What's your favorite food-related book?