The second one, From Russia with love has always been my favorite. The first four movies (including Goldfinger and Thunderball) were all reasonably close to the books. Although the gimmicks started taking over in Goldfinger, after You only live twice, it was all over.
Just as the original Sherlock Holmes stories were re-made with Jeremy Brett in the 1980's, I've always thought that someone should re-make the original Bond novels. He was more like a real person in the books and you can trace his physical and mental deterioration in the books.
YOLT’s biggest problem is that it became far too cartoonish. Connery’s experience with making it in Japan (especially to the point that fearless and crazy fans were going so far as to get his autograph by climbing into his bathroom stall) apparently caused him to decide to prematurely conclude his playing the role (and depriving us of seeing him in ostensibly the best-written JB film in OHMSS).