First on the list!! "Bibliotheca Mystica de Dantalian" .

You would surely love this one. It is a light novel written by Gakuto Mikumo. It was serialized as an anime and there was also a manga of it. To summarize it, the story centers on Hugh Anthony Disward, the keywarden to the library of Bibliotheca Mystica de Dantalian which holds thousands of phantom books. Phantom Books are books that holds supernatural powers. And basically, the story goes on as he and the library which is in the form of a girl goes on a journey while searching for the other phantom books that his grandfather had lent to others before he died. What I really love about this one is that, it is full of interesting topics. It explores dark scenarios by inserting ancient myths from different fields. It makes your finger,body,mind and curiosity to itch and search about those things to confirm if they are facts. Also, the way how the author depicts about the nature of the Biblioprincesses will surely pick your curiosity! You'd better watch this one. But the thing is, the anime is too short. After I finished the anime, it felt like I was left on hanging and it made me so flustered and angry. Well, of course the end result was that I searched for the translated light novel. :) .