Kreia. Even though she died a sith she still held more Jedi teachings than any other before. She even foresaw the Vong War, Emperor Palpatine and such. It was why she wanted to the force to be destroyed, to halt the death to come in the future. I mean for fucks sake Ithor was destroyed yet again for the sixth time. She was probably the most selfless character in any series I've come across.
