Although I agree with Anarda's conclusion that good realistic teen fiction had a resurgence this year, the fact remains that there are so many great fantasy books and series for teens out there right now--some lighthearted, some dark, some set in worlds much like our own while others are set in places only their author can describe. I will mention three series I loved in 2013, with apologies to all those I know I am missing:
The Chronicles of Kazam, books 1 and 2, by Jasper Fforde
Fforde, author of the Thursday Next series, has branched out into young adult fiction by creating a charming and delightful cast of characters in a kingdom eerily similar to the British isles, in which magic, formerly prevalent, has begun to wane. The protagonist is a plucky young foundling named Jennifer Strange, who is working as the temporary manager of Kazam, an employment agency for magicians (and what a quirky bunch they are!). But an unexpected prescient vision by one of them reveals that the last dragon in the world is going to die, and that Jennifer is destined to be the Last Dragonslayer! She's not too thrilled about either eventuality, as you can imagine... I can't wait for Book #3!
Mirrorworld, books 1 and 2, by Cornelia Funke
Many know the worlds of Cornelia Funke, and most of them are for children and tweens. But these books, while completely acceptable for 6th-graders to read (as we discovered in 6+7 Book Club), are so dark and strange, and so lyrically imagined and written, that teens of all ages will want to visit Mirrorworld.
Ever since Jacob Reckless was a child, he has been escaping to a hidden world through a mirror in his father's abandoned study, a world that bears a striking resemblance to the stories we in this world know as fairy tales--but dark and twisted ones, reminiscent more of the original tales from the Brothers Grimm. He has made a name for himself as an adventurer and a finder of enchanted items, and has lived an exciting dual life; but all that is about to change. His brother, Will, follows him through the portal and is infected with a curse that is turning him slowly to stone. Jacob will do anything to reverse the dark spell before it's too late...
The lush vividness of her language, the darkness of the tales on which the narrative is based, the charismatic characters...although the first book was hard to get into at first, once I immersed myself in Funke's Mirrorworld, I revised my opinion to marvelous! Cornelia says there will be at least three more books in this series, so stay tuned.
The Lumatere Chronicles, books 1-3, by Melina Marchetta
A false king has taken over a kingdom, slaying the entire royal family; he has also put to death the high priestess of one of the goddesses worshipped there. As she dies, she curses the kingdom so that all still in it are trapped inside, and all outside its borders are exiled. The story starts 10 years later, as Finnikin, best friend of the slain young prince of Lumatere, meets Evanjelin, a strange novice from a religious retreat house who claims that they both have a role in restoring the kingdom.
Froi of the Exiles was my pick for favorite fantasy of 2012, so it's no surprise that I also loved 2013's final book in the trilogy, Quintana of Charyn. This is one of those series that is a little bit of a sell, because while I really liked the first book, it didn't bowl me over. But I liked it enough to read book #2, and that book was so gripping, with vivid character interaction, beautiful language, and gorgeous world-building, that I haven't stopped talking about it since. Ditto for the third. So if you start this series with Finnikin (which you must, or you won't understand a thing) and your reaction is "meh" (although I don't think it will be, because it's a solid effort), keep going until you can read the other two and see if you don't agree with me!
If you read and liked Graceling and Bitterblue, by Kristin Cashore, these books by Marchetta are definitely for you!