How does hype affect how you approach a book?

I was originally just thinking about with regard to classics as I have just finished reading The Catcher in the Rye. It's been on my radar as a kind of must read book for ages for some reason - maybe I have absorbed some of those 100 books to read before you die lists without realising - and I found it in my parents' house and figured I'd see what it was all about. I really enjoyed the book and love the way things and people are described in it but it didn't grip me in a way I'm used to by a good book - can't put it down, end up reading until stupid o'clock in the morning...but I probably read too much fantasy. But it left me wondering what all the fuss was about.

I was given Northern Lights, the first of the His Dark Materials trilogy, by my brother for Christmas before I'd heard of it and so had no idea of all the hype and I loved it, as well as the other two. I think I started reading Harry Potter without really knowing that people had gone crazy for it as well - tho I queued up to get the last book without realising I hadn't read the book before I couldn't remember anything that had happened in the book before that so ended up starting back at 5. I read 5, 6 and 7 in 3 days I think <3 mmm, unrelated.

ANYway. Do you ever find yourself a bit disappointed when you come to the end of a book? I try and make up my own mind after reading things but sometimes can't help but think was that it?

So, er, thoughts?