Just posted this in a first line discussion on This Space. Not just a first line, but a first line of a first book:
"In Melton Mowbray in 1875 at an auction of articles of 'curiosity and worth', my great-grandfather, in the company of M his friend, bid for the penis of Captain Nicholls who died in Horsemonger jail in 1873."
Ian McEwan, 'Solid Geometry', from First Love, Last Rites
Can anyone beat that for a debut?
(Update, Feb 9: go here for more.)