I have always thought INFP for him. The impression I got from the book was that he was just a spoiled brat that wanted to spite the world. To me, he just reeked of elitism. *Do away with society and all it's capitalistic evils...it's all pointless* It was his fault that he died but it was still sad. To go that extreme on his values seems like really high Fi...going against the grain.
However, he had A LOT of guts which was admirable.
EDIT: I apologize if that came off really harsh and offended anyone.