Darren Aronofsky .. brilliant director: Requiem for a Dream, The Fountain, The Wrestler.
As a dance movie, Black Swan can't compare to Neve Campbell's The Company, but as a psychological study on the descent into madness, it's way up there. Mind you, not nearly as powerful as Requiem.
Of course, you need to steel yourself to watch Requiem. It pretty much defines downward spiral. Not an easy movie to watch, but I'm glad I did.