Sincerely, and without wanting to seem high brow or pretentious -
It would have to be Benedictus by Karl Jenkins, The Armed Man: A Mass for Peace.
Beautiful and moving, though I would spend my time in tears so I'd have to have something jaunty to counteract it - maybe Walking on Sunshine by Katrina & The Waves..... (if I were stranded on a bleeding desert island, I'd at least hope the sun was shining).
Book? Difficult decision. Tess of the D'Urbevilles or something laugh out loud such as One Day by David Nicholls.