The Giver by Lois Lowry
I bought the book after seeing that it was a Newbery Medal winner, an award which I had great respect for. I just read the book yesterday, and I have to say it didn't disappoint me. No, that's way understated. Almost from the moment Jonas became the Receiver, I was crying every page. Beautifully crafted, with a deep message. And the ending was awesome too.
I've read some criticisms that the book's symbolism is too heavy-handed, but I didn't feel that. It had just enough emotional power, just the right story, just the right plot. At first, the first impression I got after reviewing the novel was that it was a Christian allegory, but now that I think back I think the symbolism was more Buddhist than anything else.
Anyways, I think everyone should read it. It is certainly a great ride for children and adults alike.