The Mustang's always been a favorite of mine and...although the Germans were hurting by the time it came out...it still put that final nail in the coffin, and also were able to escort the bombers all the way to Berlin and back.
I'd go for the Mustang with the Me-262 and Tempest close behind. The deciding factor for me is the fact that the P-51 had the more impact on the War than the other two which means if the Me-262 had not been delayed in its deployment it would have been the greatest.
Besides the P-51D didn't have the highest performance. Had it been necessary the P-51H would have dealt with the latest Axis fighters.