I'm the kind of person who always likes the book way more than the movie, but this book was an exception to my rule: I enjoyed the movie more than the book.
When I read fantasy, I like getting into the world where the story takes place, but I couldn't get into Narnia. Everything seemed too plain for my taste (even for a children's book). There was the good and the bad. The good won. End of the story. I was expecting a little more background from a book.
It was ok, but I got bored.
I warn you (if someone happens to be reading this) that my review might get a little too subjective, but there were two main points I disliked:
1) The religious component. Yes, I know I should have expected it, since I was reading C.S.Lewis, but I didn't expect an express mention of the myth of Lilith. I've always had issues with Lilith being the bad one, mostly because of what it represents for women. So I didn't like at all the whole "Oh, the witch is bad because she descends from Lilith". I was ok with the "son of adam and daughter of eve" mention, even if I'm not religious myself, but the mix of creationism and fairy tale-like fantasy didn't work for me.
2) The sexism. I know I should take into account the time when the book was written, but I still find the explicit differentiation made between the girls and Peter quite unnecessary. And the thing about "girls should not fight" drove me nuts. I'd had been ok with the girls not fighting the same as Peter if it hadn't been so explicitly stated.
Flat story. Flat characters. An OK book, but not that great. I'll be honest: I was expecting more. But I guess I'd give the following book in the series a chance.
Favorite character: I think I'd go for Lucy. And the Professor.