Skellig

by David Almond

Unhappy about his baby sister's illness and the chaos of moving into a dilapidated old house, Michael retreats to the garage and finds a mysterious stranger who is something like a bird and something like an angel...
(Summary retrieved from goodreads.com)

What a deeply moving book. It is crammed full of many important themes without being overwhelming: the fear of loss, of being different, starting over. Ideas we can all relate to, regardless of age. This was also one of the few time I thought the movie adaptation was actually quite good. I would recommend this book to anyone of any age. I've always thought that stories aimed at a specific age group (especially younger ones) can still be enjoyed by anyone, this is yet another perfect example of that.