In terms of quality of play, I'd have to say that his win over Davydenko in the TMC is right near the top. I don't think I've seen him play worse, yet win so comfortably.
No kidding!!!!!!!! His tennis teachers must have been dying of a heart attack if they watched this match. He was missing shots that not even an amateur would miss. His form was absolutely pathetic, they do say that pathetic form from an opponent may actually drag you with it, Davydenko may have contributed too.
Yet it was all in Federer's hand. So for sure this was his poorest match quality wise.