Best for what?
Planes are like tools, each has something that it is good at. Some are more specialized (A6m = turn)
Some are faster (la7) others have more armament (N1k2).
However if you want a decent plane, that is fair at most things, easy to fly, and easy to learn basic ACM in, its hard to beat the Spitfire 8. Its not uber in any way compared to its other spit brethren. It can't outturn a spit 5, nor outrun or outclimb a spit 16. But it does all things fairly well. In capable hands it is truly a jack of all trades.
Now if you truly want the "best of the best" your talking perk planes for the most part. Good luck accumulating the points to fly those late war monsters.
Exceptions would be the spit 16, la7, 109k4, p51.
All fast, all very capable killers if flown well.