11: The Reckoning: Darkest Powers Book Three, by Kelley Armstrong (2010 hardcover)

I read The Summoning, the first book in this series, when I was in Italy during the summer of 2008--my pre-Kindle days when the main criteria for travel reading was that it offer entertainment in paperback form.  I wouldn't put it forward as one of the best teen series: indeed, there are likely a dozen others I'd name first.  However, Armstrong's tale of teens coming to terms with their supernatural status (wizard, necromancer, witch, werewolf, etc.) under the all-too-watchful eye of an institute they find out genetically altered said powers, is entertaining.  The books have all the requisite teen-girl themes: angst and alienation, clueless/hostile/missing parents, and romance abound.  As a bonus, the female protagonist, Chloe Saunders, gains both supernatural strength and personal character throughout the series, gaining confidence and learning to stand up for herself and her friends in ways not always exhibited by female leads in other popular teen books (i.e. The Twilight series). There's plenty of action and a brooding werewolf.  What else can a girl ask for?