Forgive me if this has come up before, but does anyone remember the BBC Radio adaptions of the Chronicles of Narnia? They were broadcast quite some time ago, well over ten years ago, but they've stuck in my memory. One thing that especially stands out was the Horse and His Boy, especially that scene where Aslan meets Shasta in the mist when crossing into Narnia.
It was just so well done. Listening brought me the same feeling of awe I always felt on reading that scene in the book.
All seven books were adapted and as far as I remember they were very faithful to the source material. The only change I recall was in The Last Battle when Emeth met Aslan after everyone Jill and Eustace came in through the Stable Door, instead of before.