I make every attempt to read a book before I see its counterpart on the big (or even small) screen. Having always been a "reader," I tend to believe that the written word is more entertaining and "better" than the movie.
I say that because I have found it to be true. It is difficult to fold in as much detail in a movie as can be found in the pages of a book. And it is also difficult to leave to one's imagination what is left there by words when there are visuals provided on a screen. That use of the imagination often makes all the difference in making the book better!
I believe that movie-makers do what they do well; don't get me wrong. I enjoy movies of all sorts and most often even those where I have read the book and know the story. I enjoy them more if the story line is not altered and if the actors chosen meet the imagined characters I have created. That is not always the case.
The first movie I saw that stands out as being rather horrid was "The Shining" starring Jack Nicholson. He did not match the description I had in my mind of the handy man hotel keeper and I recall literally walking out of the theater when he said "Here's Johnny." I believe Stephen King was also a bit disappointed in that showing and made another version of the movie himself.
Other times, the movies follow right along and the actors and actresses portray their characters as if they were wedged between the pages of the book. A prime is example is the not so distant past release of "The Help." The movie came out and was a huge success; however, I could not see it until I read the book. Of course getting a copy of the book from the library proved difficult as apparently other people felt the same way I did. After reading it, I watched the movie and was pleasantly surprised that it followed the details.
Books based on the works of Nicholas Sparks also seem to closely follow the written word. I have enjoyed each of his books and subsequent movies made from them.
I must admit, as I write this, that there are some movies that I have seen without reading the books and don't know how they could be improved upon. Those include "Gone With the Wind" and even the mini-series "Lonesome Dove." Somehow Clark Gable, Robert Duvall and Tommy Lee Jones just can't be improved upon!
In a day and age when everything is technological and immediate, I continue to enjoy the turning of a page (an actual paper page although I admit to having E-books on my Ipad for times when I don't have a real book with me). I encourage my children to read actual books and not rely on the movies. Perhaps that is the former English teacher in me, too, as I recall those high school students trying to convince me they read Romeo and Juliet rather than watching the movie!