Huckleberry Finn is so warm and lovely, I'd definitely keep pressing it on him.
A Time of Gifts is the ultimate travel read, by Patrick Leigh Fermor. I don't know anyone who wouldn't enjoy this. He's written loads of other books about his travels too.
Finding Cassie Crazy and Feeling Sorry for Celia- v. funny, by Australian author Jacklyn Moriarty.
Crusade in Jeans, Thea Beckman.
The Chosen by Chaim Potok is about the friendship/trials of two teenage boys. Then once he's finished that he'll be hooked! so could discover the rest of his amazing books.
Would he be interested in diaries? like Etty Hillesum, Goncourts, the obvious ones like Anne Frank etc.
Also, there are loads of history books by popular historians out at the moment. Lots about 20th century events like the whole story of the Berlin Wall which is fascinating to any kid. I loved 'The Berlin Wall' by Frederick Taylor and read 'Revolution 1989' by Victor Sebestyen when I was on holiday.
Viragos? less explicit ones, obviously. But no seriously, why the hell not.....just cos he's a boy. They're brilliant most of them.
The Moon and Sixpence might be good. V. easy language, about an arty man, everyone's attracted to artists, wild and unpredictable people....
Maupassant? Boule de Suif etc. They're what everyone reads when first learning French (well, 20 years ago. Now, of course, they wouldn't dream of giving us anything so complicated).
Death in Venice, Thomas Mann. 60 page novella. Beautiful desperate story.
Perfume, Patrick Suskind, everyone has an opinion on this so a Y8 boy certainly will.
About a Boy, Nick Hornby and Adrian Mole
Has he read Flour Babies and Goggle Eyes etc?
Don Camillo's always funny. So is Jennings, it's a laugh a page. Definitely worth scouring the charity shops for or splashing out a bit on Amazon.
Feminist fairy tales?
E.M. Forster- Maurice? about gay clever-stupid/naive teenagers.
The Road, or is that a bit too dark? It's what you make of it I think.
Roald Dahl: Storyteller by Donald Sturrock (I think that's his name). Everyone loves Roald Dahl, here's a fab and well written biog of him.
The Montessori Method- might challenge his view of schooling, his own schooling etc?