Who is the Strongest Jedi Knight?

Besides Lucas saying Luke was the strongest, I'm gonna have to say I would agree... I know he lacked the training every other Jedi received but when facing his father he held his own (I know. Vader didn't want to kill him but wanted to have him join him) but in the end even lacking the training he was able to change his father back from the dark side. That it definitely saying something about Luke's strengths.