First the Middle Grade: I guess I would classify Lisa Graff's A Tangle of Knots as magical realism, as it is set in a world where people have "Talents," so something that they are unnaturally skilled at. This could be something as awesome as being able to bake the perfect cake for any person, or as mundane as being able to successfully aim your spit to hit anything. I'm not very far in the book yet, but from what I can tell, it is the story of a young orphan named Cady whose life collides with a whole cast of unique characters when she is adopted and moves into a new apartment building. So far it is light-hearted and quirky and I am really, really enjoying it!
And the Young Adult: The Thousandth Floor by Katharine McGee has been getting a lot of buzz the last few months for being "Gossip Girl in the future." That's a pretty dated reference though, and probably means nothing to my high school readers... and now I'm feeling old...
Anyways, it's set in Manhattan about 100 years in the future, a world where giant skyscrapers have basically become entire cities (thus the title!). The higher you live in the Tower, the more wealth and prestige you have. This book is basically about the lives and drama of a bunch of uber-wealthy teenagers. It's fabulous. I'm about halfway done and already have a waiting list of people who want to read it after me.