Movies or Books?

I don't know about any of you, but when I hear about a book I really love being adapted into a movie...I can't help but grimace.   I don't like my favourite books being crammed into a two hour whirlwind where we can't understand the motives behind the characters action, or who they even are.  Books allow for beautiful descriptions and lets the reader get inside their minds.  You just don't get that with movies.  Saying that - there also things you can do with movies that you can't do with books.  So who wins?  What's better - the book or the movie?  Is there any clear winner?

If I have really enjoyed a book, chances are I'm not going to enjoy the movie as much.  As any avid reader or writer will tell you, the characters become real for you.  You hear their voice in your head, you see their smiles and secret looks - you know them.  The actor that plays said character is never what you expect.  For an example I will use The Time Travellers Wife.  Eric Bana,  whilst insanely gorgeous, just wasn't Henry for me.  He was too...I don't know, good-looking for me.  I always imagined Henry to be on the skinny side and rough round the edges.  But saying that, I liked the movie.  Why?  In my mind  I made them two completely different things.  If I can separate the two from each other, I can appreciate each on their own.  If I stop comparing every little thing, I enjoyed the experience much more.

Having said that, sometimes the movie really nails the tone of the book.  The characters are perfectly casted, the plot runs smoothly and no major developments are left out.  Yesterday I finished reading The Boy in the Stripped Pyjamas.  I saw the movie awhile ago, and perhaps because I saw it first, I really enjoyed it.  But more than that, I thought it was a great adaptation of the book.  Rupert Friend who played Lt. Kotler, in my opinion, did an excellent job with the part and was able to put across the desperation to please his superior and disgusting hatred in a way that really did the book justice.

So what do you guys prefer?  The movies or the books?  How about both?  Or is the general opinion a sharp hiss when the word 'adaptation' is mentioned?