What in your opinion is the best book that you haven't liked?

Over the summer lots of my friends (as well as my mom) began to read the Twilight books. At the time I was reading Harry Potter and the Half Blood Prince, so I didn't began to read it until a couple months later. While my friends all loved the book and couldn't say anything bad about it, I was much more disappointed. People I know had compared it to Harry Potter, which I love, but I really don't see this. Sure the book is fantasy, but that is probably the only similarity. I didn't enjoy the book until near the end when more action started to kick in. I may read the next book, but unlike everyone else I know, I didn't rush out to get it the second I finished the first.