The most memorable book/movie combination for me in recent years was the Millennium Trilogy, a series of three novels by Stieg Larsson. The three volumes in the series were The Girl with the Dragon Tattoo, The Girl Who Played with Fire, and The Girl Who Kicked the Hornet's Nest. I saw the movies first, in their European versions. I sort of remember seeing the American re-takes, but the European productions were just too hard to beat. It's a humdinger of a psychological thriller, which on several occasions gave me the feeling I was being kicked in the gut and having my teeth drilled. The general mood throughout the series was intense, and that's putting it mildly.
The plotline is complex, and watching the movie it was sometimes hard to remember what character was threatening to do what nasty to what other character, so I bought the book in order to be able to leaf back and forth to follow the threads of action. The book helped me follow some of the subtle connections, and I'm glad I did that. However my settled opinion after the entire experience is that the book was a work of imaginative genius, but the movie was an even better work of movie production, largely because the casting, acting and direction were all excellent, and the evil characters were so fucking evil I wanted to eat their livers. However the book was for me indispensable to a better appreciation of the movie. As with many other great works of imagination, one viewing/reading is not enough to absorb all the thrills and tickles.
As for the complaint that a two-hour movie is not enough to give a fair picture of all the words in the novel, the Brits came up with the solution to that, which is to include every word of dialog from the novel in the movie script, and then let it run as many hours as it takes, for presentation in a TV series. They did that with Somerset Maugham's Brideshead Revisited. With the movie you get casting, which is an under-appreciated art that literally brings the novel's character to life; you get settings, including scenes shot in appropriate weather, which induces a mood; you get music, which does so much to enhance and amplify mood; you get costume design, in which the clothes make the man and woman; you get sets, which include architecture and interior design. You get so many pictures within pictures, each of which speaks thousands of words that would make the literary work fill too many shelves in a library. In short, you can cram an overload of images into a movie that is beyond the power of the written word. So, another example of a great novel becoming the springboard for an even greater film production.
Nobody does drama like the Brits.