Completely agree on The Golden Compass. The first mistake was calling it "The Golden Compass" to begin with, and then it all went down hill from there. (If Harry Potter could have different titles in UK and US, why couldn't Northern Lights?) It was also a huge big fat waste of Eva Green, who would have been a perfect Serafina Pekkala if she had been playing the role in a better film. Pity, because His Dark Materials really is a fantastic series of books.
Harry Potter - I completely love the books, and I do watch the films, and there are parts of the films that are spot on, and some of the casting was perfect, but the films just always disappoint me. I think Harry Potter would have worked far better as a high budget television series. Not because the stories aren't cinematic enough, but just because it was the detail in the books that I loved, and so much had to be cut for the films.
I preferred The Lion, The Witch and The Wardrobe film to the book though. I'm not a fan of CS Lewis's writing. Even as a six year old, I found his writing patronising, and as an adult, I've found his adult books like reading an academic essay. But the books are relatively short and lacking in detail and actually, I think translate very well to screen as a result. Sadly the second and third films deviated too much from the source material, and ended up being a bit confused and a bit of a mess, which was a shame.
Interesting some people are saying they preferred the film version of Atonement; I did really enjoy the film, but I ultimately preferred the book. In the book the ending is written so poetically and it sort of drifts along and it's almost like Briony's in a dream, and it also (to me, anyway!) shows that she's not really ever grown up, she's still in denial and still the fantasist that she always was. Whereas I felt the ending in the film was a little bit abrupt and cold.