A little backstory on this one - this was the first series I hit after reading the Twilight series, and I loved it. 
 Deliciously dark, these are not nice, gentle fairies. You do not want to mess with the "fair folk". 
 The MC is a changeling - meant to break a covenenat so that the unseelie will be free to cavort in th human world unencumbered. 
 I really liked this - from the MC finding out her real heritage, to the intro to the fairy court, and everything else. Lots of fun to read.