This is damn near a trick question. I hear some of you guys saying the P-51. Yes, it is a good fighter, but it only served in the tail end of the war so it didn't get as much combat as other planes.
In terms of the most enemy planes shot down by one single aircraft design, that honor is bestowed upon the B-17 bomber.
For the most fighter vs fighter kills, that is the Me109.
For the highest kill to death ratio, that is the Corsair.
[ 09-29-2001: Message edited by: LtHans ]