On looks and apparent capability, the Ki-61, which apparently outperformed the Emil in Japanese tests and was somewhat more powerfully armed than the Folgore. But as noted, by the time it was in widespread service the DB601 was old hat
I love how all the Italian fighters look but I'd consider the C.202's lack of firepower a pretty glaring weak spot. 2 Breda 12.7mm (which were notably weaker than Browning .50's, smaller shell) and two 7.7mm wasn't too great.