By total kills only is the P-51 number one. I might point out that by deaths it ranks a close second.
From the K/D I get that the Tempest is best overall bomber kill with a K/D ratio of 13:1 followed by the 262 at 8:1. My favorite ride, the 190A-5, is a respectable 3:1.
to the brave attempting to stem the B-17 hoards in their TBMs!