On Her Majesty's Secret Service. Best plot, great score, best Bond girl, and that girl is played by Diana Rigg. Had Connery been involved - and I speak as a dyed-in-the-wool fan of Connery's Bond - it would have been a much poorer movie. As it is, it's easily the best of the lot IMO.
Having said that, Goldfinger and From Russia With Love aren't bad, either.
Having said that, Goldfinger and From Russia With Love aren't bad, either.