I just finished watching "3 Days of the Condor." One of the great '70s paranoid thrillers. Holds up well.
It's also better than the book it was based on ("Six Days of the Condor"). Same is true of another movie from around then: the original "Taking of Pelham 1 2 3."
The only other better-than-the-book movie I can think of right now is "Bridges of Madison County." I couldn't finish the book but thought the movie was great.
Can anyone recommend another movie that's better than the book that inspired it?