Of the Bond books I’ve read so far, I would have to say that On Her Majesty’s Secret Service, by Ian Fleming, is one of his best.
This book encompasses a lot for changes for Bond. Picking up Bond’s life after Thunderball, Bond is about ready to quit his job as a 00 after becoming discouraged tracking down Ernst Blofeld, the leader of SPECTRE, and is just ready to hand in his resignation letter. But a series of events involving money and a woman at a casino soon leads Bond into the depths of the French mafia. From there, he receives a tip on the whereabouts of Blofeld, and Bond goes undercover to investigate Blofeld’s operation. But before he leaves, he finds that he has fallen in love with the woman from the casino, Tracy—true love, perhaps for the first time in his life.
While on the mountain, Bond uncovers a dire plot involving biowarfare and the action really picks up from there. However, the most emotional moments occur when Bond gets back together with Tracy, and his life is changed forever.
This story is good not only because of the Bond action we have come to expect, but also because we get to see a personal and emotional side of him not often shown.
I have not seen the movie version of the book yet – my understanding is that it stars George Lazenby as Bond, instead of Sean Connery, Daniel Craig, Roger Moore, Timothy Dalton, or Pierce Brosnan.