Any recomendations for the Book Festival?

Would prefer sf or mainstream, definitely no YA, trilogies, trad fantasy...

It's an underwhelming year in general. The SF one that stands out is Catherine Chanter & Emily St John Mandel, the latter having just won a couple of major awards for Station Eleven. (It left me underwhelmed but most other people I know were suitably whelmed).
Ben Aaronvitch is there as well but I haven't read him so can't say much. Others that may be of interest are Aleksandar Hemon, Tom McCarthy and Matt Haig.

Thanks for the heads-up, tickets bought for Mandel, who is in my to-read pile!