John Green, while also a vlogbrother and semi-professional FIFA player, is primarily an author of young adult novels. He has written several on his own and collaborated with other authors on a few more. Many nerdfighters enter nerdfighteria via John's novels, and copies of John's books in stores and libraries have been the target of nerdfighter noting (i.e. leaving a note inside a book copy, introducing the reader to nerdfighteria and urging them to watch vlogbrothers). These books have won various critical acclaim, including receiving the Printz Award, being optioned by movie studios, and reaching the New York Time's bestsellers list.
John's books are:
The Fault In Our Stars
Looking for Alaska
An Abundance of Katherines
Will Grayson Will Grayson (with David Levithan)
Let It Snow (with Maureen Johnson and Lauren Myracle)