by George MacDonald Fraser
The villain of Tom Brown's Schooldays (and so the original Malfoy), having been sent home for getting drunk, gets an unexpectedly early start on adult life. He's a thoroughgoing scoundrel, as he himself will be the first to tell you, and so he goes from strength to strength. On rare occasions, he has a moment of weakness and does a good thing, and for these failures the moral universe punishes him severely, but character and his intrinsic terribleness win out in the end. The first in a long, literate series.