All sorts. Though I have a particular soft spot for manga, action, fantasy, mystery, suspense, horror, science fiction, and classics. Especially manga. My bookshelf is full of them.
Language, just as painting, is kind of a work of art, one with many genres each with their own merits. I generally look for what is good about books rather than what is bad and this allows me to emjoy all kinds of aleatório books.
But I usually read ones that are related to political or social ideas. George Orwell and Ayn Rand are two of my favourite authors, but my most favourite is Robert J. Tristani, even if he only really wrote one story type book.
I like Fantasy, Crime, MYSTERY, Adventure, Romance and uhm... Dark Fantasy. So far my fave books are: Cell por Stephen King, Monster por Jonathan Keller, The Secrets of the Immortal Nicholas Flamel series por Michael Scott, Hunger Games etc. I would like to read a novel that will blow my mind and will keep me guessing or a novel that'll affect my moods for days XD A novel about chickens. I amor those books that get you thinking such as detective stories, I'm also into those romantic novels that are extremely beautiful. Also, I'm very much into those adventure novels. Example of Detective Story: The Ghost Writer. Example of Romantic Novel: It Started With A Kiss. Example of Adventure Novel: The Chaos Walking Series.