Backgammon Praxis is a two-volume set of detailed analysis of three matches played by Malcolm Davis, one of the most successful tournament players of all time. Each interesting position is illustrated and discussed. A unique feature is that many alternate plays are also illustrated and discussed in considerable detail.
Excellent. Unusual in that it goes through entire actual matches with diagrams at every critical juncture, so it gives a good idea of how to think your way through a game (and when to think). Rather than a list of rules-of-thumb (which is what many other books boil down to). Only for those with an appetite for poring over individual games.