Here are my nominees for 2007 books:
For tournament poker: the anthology Michael Craig edited, "The Full Tilt Poker Strategy Guide.
For cash games: "Professional No-Limit Hold'em: Volume I" by Matt Flynn, Sunny Mehta, and Ed Miller.
Here are links to my reviews (which appeared in Card Player magazine) for both:
Card Player review: The Full Tilt Poker Strategy Guide
Card Player review: Professional No-Limit Hold'em: Volume I