He's already finished the more popular YA series, like for example: Twilight, Eragon, Harry Potter, Golden Compass. One of his favorite authors is John Connolly. Right now he's enjoying Wicked, and all of those books by that author. I'm already force feeding him Clive Barker's Abarat, and all of Neil Gaiman's work. With a little bit of arm twisting he is also supposed to read the the Charles de Lint books as well. So you don't have to bother recommending me those books.
He does not like vampire books or books with heavy romance. He likes happy and light books, and generally something easy to read. So George Martin will probably not be his cup of tea or any other author along those lines. He also does not like mangas or graphic novels. (Sorry, I tried!) He does not mind books with a female lead character, but he does prefer a more masculine touch. Magical creatures are always a plus.
Any recommendations you can give me will be highly appreciated. If you can even give me a brief summary of those books, it would be even more helpful to me. Thanks!