Movies better than books? Not inconceivable
A couple of expert movie watchers have shared their views (see comments for If Film Viewing is Wrong...), even raising this question: Are we allowed to believe that some movies are better than books? I hope so, because a couple instantly came to mind.
Surpassing the quality of an excellent book is a challenge, but, at least for this viewer, Gettysburg did that. Michael Shaara's The Killer Angels, the novel behind it, is a top-notch narrative. However, the film version seemed even more effective in relating military decisions to the experiences and personalities of the leaders responsible for them.
To Kill a Mockingbird comes as close to perfect as a book gets, but the casting and sensory impressions of Southern culture in the movie trumped even that. And then there was Gregory Peck, about whom no further comment is required.
Sound, movement, and costumes don't constitute an unfair advantage over print when you consider how many poor choices they make possible. We've all seen productions so laden with inappropriate period details (think Western heroines sporting bouffant hairstyles and zippers, or World War I movies with equipment not invented until World War II) that even a masterful plot lost credibility early on. And, given that we all picture the characters in precise detail while we read, the casting director's picks are guaranteed to alienate at least some viewers.
So, book vs. movie is probably a fair fight. One of the rules in that contest should be that a movie inspired by the book should retain the same title as the book. Fans intrigued by a screen version and wishing to follow up with the novel could proceed so much more happily if they weren't presented with a riddle to solve on the way to the bookshelf.
In some instances, a film actually flatters the book, either by taking a slight but interesting premise and developing it more fully or by editing the contents beautifully. The Princess Bride comes to mind...