Movies being two dimensional allow the closest depiction of the Makers' imagination. But to churn out that exact desired effect, the Maker is dependent on diverse factors (actors, animation etc.) – the "end product" might not be the "intended product". Again, there's the time constraint. And isn't the Maker yet another artist and would he/could he breathe easy till he has made his own additions and subtractions? The Book, on the other hand, is a two man show – if the Writer is the God, so is the Reader. One describes, the other imagines. Besides, words can engulf details the eyes might miss on-screen. What a turn of head and batting of an eye-lid did in 2 sec, in the book it might be two pages with everything from the length of her lashes, her ambrosial smell, to how she heaved under his stare and the exact thoughts racing through her mind. In the end, both are work of art and to the respective artist, we should give it.
Take one of my most loved novels, The Color Purple (1982) by Alice Walker, for instance. One of those Most Challenged Books of that age, The Color Purple is a Feministic novel made of a series of letters, that sum up the dire straits of black women in Southern US, that of the black natives in Africa and that of women, in those time, in general. Stephen Spielberg's star studded movie had Whoopi Goldberg (as central protagonist Celie) and Oprah Winfrey (Celie's foil Sofia), and although it looked shrunk and barely touched upon few core themes like female homosexuality – you end up loving the film just as much. Please listen to Miss Celie's blues. It played in my head the whole week thereafter and is, even now, as I write it.
I would not know how was my favorite Forest Gump, Shawshank Redemption, The Curious Case of Benjamin Button, Slumdog Millionaire, The Reader, Big Fish, Shrek, and needless to repeat, Harry Potter, worded in their Original versions. But if someday I happen to settle down with their novel, would I will love these wonderful movies any less? I think not.
P.S.: Here's a list of Books turn Movie you might want to surf through.