I just finished reading "Let the Right One In" by John Lindvist. Awesome book. In a rare turn I think the novel actually made me appreciate the movie more than when I first watched it. Also, I no longer care for the American remake at all. I don't think the film makers actually read the book at all. I watched it again recently (while I was in the middle of the novel) and I got the feeling that it was purely based on the original movie and nothing else.
Next up is "Legion" by William Blatty. I read this one years ago (when I was 12 I think). This one also made me appreciate the movie more despite the studio insisting on tying it more closely to The Exorcist than the novel did. Detective Kinderman is probably one of my favourite characters in any book.