I had a really hard time deciding, there are a lot of considerations.
If the priority was long range escort fighter, the P-51H and P-47N would take it, with a nod to the P-38L as well. I prefer the good ol' Jug out of this trio but the Mustang was no slouch by any means. Was considering the P-82B on here as well but I don't think that was in operation by '46.
If you want a fighter with excellent multirole capability it would be a real scuffle between the F4U-5, Sea Hornet, Sea Fury, F7F, P-47N (again) and maybe the Tempest as well. Out of that lot I give it to the Sea Fury after the bombs are dropped but the Corsair is REALLY close, and was the better attack aircraft. Both managed to take down at LEAST one MiG-15 during Korea, a testament to good design (and good pilots).
Best dogfighters? Spitfire, F8F, Yak, La-9, the latter two being almost unmatched under 14,000 feet (typical Eastern front conditions). Yak-9U being mostly hamstrung by its crappy armament.
I settled on Grumman's hot rod out of sheer raw performance and (I'm a superficial bastard) brutish good looks. While a good pilot in any of these planes would be able to give the Bearcat a run--some had better agility, some had better top speed, a lot had better range, better firepower/payload etc. etc.--the F8F with its explosive climb rate (in excess of some early jets) and acceleration gives it a huge advantage in most flight regimes. Couple it with four 20mm cannon in later marks and you had the ultimate piston-powered interceptor--and quite fittingly the ultimate Reno racer, though Sea Fury pilots I'm sure have something to say about that.