For 3 years I have been part of a Books to Film discussion group. We select the book/film as a group. Everyone reads the book on their own and then we get together and watch the film.
Much discussion is generated in how the book differs from the film, how the film was interpreted by the screen play and the Director. One thing we try and avoid is making a judgement as to which is better.
Following is a list of some of our most intriguing books; ones where both the book and the film were said to be 4****
The Diving Bell and the Butterfly
Of Mice ad Men
Cry the Beloved Country
If you want to add a variance to your book club I would suggest this format.