I've just finished the final book in Lois Lowry's trilogy that started with The Giver. Messenger is an excellent completion of Kira's and Matty's and Jonas' stories (Gathering Blue is the second book.) I thought it was a thoroughly satisfying and meaningful book in every way. I didn't think it could possibly top The Giver, and it doesn't, but at least Messenger comes close.
Messenger followed the same theme as The Giver and Gathering Blue- that we all choose how our societies run. Jonas' community decided that they were afraid of choices and so they removed almost any opportunity to make choices. Kira's society decided that they can't afford to keep anyone who doesn't fit in. And Matty's Village chooses selfishness. Lowry has a knack for telling a good story but making you think.
If you haven't read any of these books, they really are worth reading. I'm looking forward to reading them with my own children in a few years.