I've read four out of the seven Harry Potter books. The first two I enjoyed a lot (Got through Chamber of Secrets in three days), the third one was good. Forth (Goblet of Fire) didn't really do anything to capture my attention and I quit as soon as that damn tournament started. Bought Order of the Phoenix a week after it came out and have read it maybe twice. Not to say I didn't enjoy it because I thought it was brilliant.
Then I stopped. Never got around to reading Half Blood Prince or the last one. And it didn't bother me that much either.
Saw the first two movies and enjoyed them. Decided to sit my ass down and watch Harry Potter and the Half Blood Prince despite the long run time and I have to say that it felt pretty uneventful. None of the characters seemed to stand out in any way for me, it felt like a lot of things were happening yet nothing was really getting down, and I don't even I could think to call any scene a favourite. That and it felt like half a movie to me. The credits were rolling and I thought, "Oh, that's it?"
By no means was it a bad movie but it also wasn't one that I'd sit through again. Maybe it's a good thing I stopped reading when I did.