The big screen

Can books be successfully be portrayed on the big screen?

After this weekends experience I am not so sure. I have just finished reading One Day by David Nicholls,  which I would recommend. I laughed, I cried, I got attached to the characters and even threw it across the room at one point. Having loved the book so much and the film just becoming available on DVD I decided to watch it and, as with so many film adaptations, I was left disappointed and screaming at the screen! I don't know if it is just the style of the story or even because I had read the book but I found my self not connecting with the characters I had come to love so much.

There have been other book to film adaptations that have left me with a similar feeling, some not even keeping to key features of the book; High Fidelity springs to mind here! However some adaptations, like the Harry Potter series and the Twilight franchise manage to capture the essence of the books successfully, even though I still don't understand why Peeves the poltergeist didn't make the films!!

What do you think?? Should I just avoid watching the film versions of the books I read, or chance them and hope that they prolong my enjoyment?