For Middle Grade:
Government Inquisitors, crazy old wizards and secret basements abound in this fun adventure. Good for anyone who's ever wanted to make their little sister disappear. *cough*
A steampunk, spy book with elements of the Hunchback of Notre Dame and an excellent villain.
For Young Adult:
A wonderful dystopian love story, where the true nature of the society only gradually unfolds. Also quite possibly the most well-done love triangle I've ever read.
Three words: Kick. Ass. Werewolves. Seriously. If you're burned out on angsty, shape-shifting werewolves with no shirts on (*cough* Twilight *cough*), this is the book for you.
The Surgeon (Jane Rizzoli & Maura Isles, #1) by Tess Gerritsen
Yeah, there's only one in this category because I didn't read that much general fiction this year. So just buy a LOT of Tess Gerritsen, because these books are amazing. Okay?
This is a very intensive book with a lot of great ideas. I'm going to have to read it again to catch them all. But overall it's an excellent challenge to dig deeper in your writing.
This is still one of my go-to writing books. An excellent addressing of the specific problems of worldbuilding, character involvement and plot that are common to writers of speculative fiction.
Those are my gift recommendations for this holiday season. If anyone wants to add to my list in the comments section, feel free!