I have read a lot of books so choosing one is difficult, but I cast the Saga of Shadow Hunters because I like it very much.

The author is Cassandra Clare and City of Bones is the first book in the series.

The saga itself is about a fantastic world where there are the Nefilim who are the Shadowhunters and the Underground who are the werewolves, fairies, vampires and sorcerers. The shadow hunter has a duty to protect the world from the demons and fight Valentine who is a former shadow hunter who seeks to eliminate all the underground. In this context Clary (the protagonist) a worldly one who can see the demons and the hunters (normal people can not see them) discovers that she is the daughter of a shadow hunter and that her mother I erase the memories of everything related to The world of shadow hunters, also meets Jace, Alex and Isabelle Lightwood with whom he fights to defeat Valentine and recover his memories.

Also some books have been adapted to the cinema and recently appeared like a series in the tv.