I think Bernhard is so important because he really does something different in piano teaching and playing. He was the guy that showed me that I could learn in other ways. Even if I don't agree with all he says, I know that by reading that I will learn something.
Xvimbi was insightfull too because of his obsession with the body, and how he opened my eyes to that.
Ted is the revelation: someone that appeared here, in the middle of the classical pianists and students and said that he almost only improvised. Great! Great thoughts about improvisation, and really changed my approach to it.
Does Chang count too? And I also read some really nice and insightful posts from other members too, like Whynot and Lostidleinwonder.
It's difficult to choose!
Sorry for my english,
Lucas