Catherynne M. Valente has decided not to see the Chronicles of Narnia because of her love for the books and her unwillingness to have the images in her head changed to a mass produced image. She points to Lord of the Rings and what happened to that:
I love my Eowyn, I love my Faramir. I do not love Miranda Otto and David Wenham, pretty as they may be. I do not love that visions of this book are so bottom-lined now, that the wonderfully unique experience of participating with a long-dead author in creating a world which exists for no one else has been replaced by enforced communal experience, that all our worlds are the same. Though it is a different essay entirely, the ultimate and natural destiny of books is not movies, and books have their own power which movies cannot effect. What movies can do is allow us all to experience the same things in approximately the same way, which is amazing, and sometimes horrible.
I basically agree with her. It's tough to read Lord of the Rings without at some point seeing Elijah Wood as Frodo. It's frustrating. You live with it and you try to retain your original vision (even though I do enjoy the films).
But what if I had never watched the movies, never gone to the theaters and bought the DVDs. Would I be free from those images? As far as I can see, if a movie is a hit it is nearly impossible to escape. Movie merchandise is everywhere from Burger King to children's toys.
And then it hits cable. I can't channel surf by HBO without catching part of "Return of the King" right now. How many times would a lover of the books be able to go on turning the channels before they gave in and watched a few minutes?
Even the books, go to your local Barnes & Noble and look at them. There is the trilogy with Viggo Mortensen's face glaring out of it.
I often look forward to movie versions of my favorite books (next up, "A Scanner Darkly"), but I regret the way those images are plastered over everything. I still want to open those pages and read the book without thinking of the movie. Is that even possible anymore?