This question is open to interpretation a little I think…does it refer to the book you’ve most enjoyed that’s been adapted, or the best adaptation of a book?
Am I even making sense?
I think the obvious answer is Harry Potter on both counts. It would be so easy to sit here and slate the films, so so easy. "They changed this and they missed this and I LOVE GARY AS SIRIUS and this never happened and I LOVE GARY AS SIRIUS and why did they cut this and I LOVE GARY AS SIRIUS and how dare they not explain this and it's all not the same as the book" *angry face* but you know I'll be the first in line for tickets on release dates, you know I'll actually get a kick out of dissecting it, you know I'll go back to watch it three or four times, you know I'll buy the dvd, you know that I'll love it.
However! I do not wish to be obvious and I am well aware that I am at risk of looking a little bit Potter-mad, so, taking Harry Potter out of the equation, the book I liked the best that’s been made into a film is probably The Time Traveller’s Wife. I think it’s a beautiful, clever, wonderful, moving story, one that I loved as much when I revisited it as I did the first time around and I am still so angry with the film, which turned that beautiful, clever, wonderful story into a chick flick. Grrr.
My favourite adaptation is Atonement – quite possibly the best adaptation of a book that I’ve seen. I love Atonement. I love the beautiful book and I love the equally beautiful film, both of which make me cry a little.
I also feel I should give a little mention to Twilight, which made bad books into less bad films by casting RPattz!