A lot of factors to consider here. Are we talking best in terms of overall performance? In that case it's the corsair hands down. But what if we factor pilot quality in? An average pilot in a Corsair will prove why it was called the "Ensign Eliminator." And what if we are talking about impact? The F6F Hellcat flew more sorties that any other American carrier plane, had far more kills, was easy to fly. Furthermore, it is hard to overlook a 19:1 kill ratio. For that reason alone, the Hellcat gets my vote.