I am reviewing the entire series, rather than each book individually
I must say, I loved the series - richly imagined worlds, philosophical depth, emotional reach, and the people of each world. The author done amazingly well on building a multiverse where worlds exist alongside our own, each with it's own rules. We, of course, can not forget the dæmons.
I love the balance of adventure and ideas. We have danger, mystery, unexpected twists, and heartbreak.
My favourite in the series will always be The Amber Spyglass, closely following by the preceding book - The Subtle Knife.