I have raved about The Raven Boys and The Dream Thieves by Maggie Stiefvater and feel the same about the third installment, Blue Lily, Lily Blue. Given my feelings about trilogies, I am glad this is a four book series. The two middle books in a quartology (I think I may have made up this word and I like it!) do not seem to suffer from the same weaknesses as the middle book in a trilogy. While I love Stiefvater's stories, it is the beauty of the writing that draws me in most. Her descriptions are haunting or mesmerizing, or peaceful. Whatever she is going for, she achieves.
Sigh, feel like waiting for the 4th is taking an eternity.