The biggest, the worst, and the absolute hafid philosopher of all time I think would be Immanuel K-k-k-Kant. That guy is just... he's just a bad philosopher to be honest. His Metaphysics of Morals was obviously OBVIOUSLY a quack bit of useless. He wrote this funny story mind you, about how a priori reasoning was somehow "important" and whatnot and all... but he is in all honesty a quack. His "creation of the metaphysics of logic" or whatchamacallit was just a bunch of contradictions and woo... a candid philosopher who understood metaphycisist and was good in sum respects, but on the basis of his arguments he was Totally Invalid.