OK, so some might not like the idea of grinding 50Shades into the dust, but there are better books out there and enterprising PD Allen has created 3 lists thus far on Amazon to prove it to you...and every book on these lists is well worth a read!
Here they are:
Part I: http://www.amazon.com/lm/RFXL25QK3NXQB
Part 2: http://www.amazon.com/lm/R172M2VR65IREC/
Part 3: http://www.amazon.com/lm/R356BP1SZQW2XG/
Take a look!