The Darkness that Comes Before, by R. scott Bakker, and its sequels, are my favorite book series.
However, they're very divisive. They generally have only one character who is anything approaching likeable, and everyone else is a terrible terrible terrible person. If you can stand the total soul-numbing darkness and nihilism of the series, I recommend it. Otherwise, I'd try something more cheerful, like Elie Wiesel.