Probably my favorite thing fluff-wise was Genius: The Transgression.
Unfortunately, never had the chance to run a game, but the premise is solid.
"Geniuses form connections with things that aren't 'really' there for most people. Their entire essence screams to reduce reality to a handful of elegant equations that are obviously, self-evidently true. The Peerage exists almost entirely to fight this tendency, because once a Genius believes he's figured it out, he's mad. The light eats out the back of his eyes and he'll probably never see straight again."