Hmm... P51d yes, FW 190 maybe, P47 debateable, Vought Corsair debatable. Which other piston engined fighters outperformed the Supermarine Spitfire?
It depends very much on the period in WWII.
The Hawker Tempest MK.V outperformed the Spitfire MK.Xs and XIV's easely.
The FW190-D9 was a magnificent fighter.
The late war Soviets weren't bad either, like the Lavockin La- 5 and La-7 or the Yakovlev Yak-3
These are all late war developments,
In the early war period,
The Messerschmitt Bf-109 D and E series definetly ruled the skies.
If the Dutch Fokker G.I and the French Dewoitine D.520 could have proven itself longer in combat they would certainly have been magnificent.
And of course let we not forget the most brilliant of them all, in capable hands, the Mitsubishi A6M-2 and -3 Zeke, what is lacked in armour it made up in beauty and extreme manouverability
I can't think of any American fighter that really did it