David Foster Wallace, according to I Write Like, a relatively new online tool which compares your writing to a pool of well known and accomplished authors.
That was my result when I tried two short stories and the prologue to a novel. Then I tried an Amazon review and it told me I write like Dan Brown. (Not my review of Twilight, though. For that, I apparently channeled Meyer herself.)
Then I put in another novel’s prologue and it told me I write like David Foster Wallace again.
Oh, and Cormac McCarthy writes like Ursula K. Le Guin.