It was always my least favorite – I enjoyed reading it at first, and was flabbergasted to discover who opened the Chamber, but re-reading it got a bit tiring. I think it’s actually too close to the first one, spending the whole book suspecting someone (Snape/Malfoy) to find out it’s somebody else entirely, with the same “travel under Hogwarts” thing. But I think I prefer this one to PS now, maybe because I especially like when the kids are at Hogwarts, that school fascinates me, and PS spends more time introducing the wizarding world then having fun at school. Anyway, any Harry Potter book is a great book, obviously, and I can see how it’s the favorite for some, but nothing beats PoA in my heart. (Well, except for HBP, that is.)