I've only read The Long Walk by Richard Bachman. But I've seen the movie IT, which was so creepy, yet amazing. I need to read the book, and more Stephen King for that matter. Yea, the HP movies are fresher in my mind as well because I saw them more recently than I read the books. However, I do remember the 7th book the best, since I read it last (and I re-read it a bunch of times anyway). I literally bawled at the end of the last HP movie because it was over T_T haha.
Dan Brown has written Angels and Demons, Deception Point (which I have not read), The Lost Symbol, Dante's Inferno...etc. He's a great thriller/mystery/historical author...he just combines all of it into one amazing package of a book. He used to be a lawyer, you know? Isn't that crazy!
You should definitely read his books, at least the Da Vinci Code (the movie really does not do the book justice at all).