You,ve only read 4 books what do you know. The reason The film is so good is that it is based on the play rather than the book.that is why the set scenes in the film work so well.
I,d go with both of those. Cuckoos nest is still a great book though. I saw the film first and thought I would only see Nicholson when I read the book but I didn't. I saw the 6ft 4in flaming haired Irishmen.