The films are pretty straight-ahead adaptations of Fleming novels through _Live and Let Die_. After that, they were out of books they had rights to, and the films take a serious plunge in terms of actual quality. For my money, the only genuinely watchable non-adaptation example after LALD is _Goldeneye_.
I mean, note the huge jump in quality when Craig came on when they finally DID have a Fleming novel they could work from again, right?