I'm on the fence on this one.
On one hand, for example HP, I thought the movies were fantastic. I thought they were a really good adaptation from book to movie.
Thats an example of where I read the books and watched the movies.

On another hand, Eragon. I loved the book and I loved the movie, but for different reasons. I watched the movie, not as an adaptation from a book, but as a different way to tell a story about a boy and his dragon.

There are a lot of movies I've seen without reading the book, and I loved the movies, and there are some books to movies where I have no desire to read/watch at all.

I am a little curious as to when we're going to recieve completely original movies -ie, not based completely on a book- but at the moment I don't mind. Especially when they're bringing out things like Les Miserables. I really want to watch that one!