Note that contrary to what many sources claim, the P-38 Lightning did not shoot down more Japanese aircraft in WWII than any other American or Allied aircraft.  The numbers do not support that statement. (In red below)  The P-38 with 1,857 victories came in third behind the F6F Hellcat with 5,160, and the F4U Corsair with 2,140. What is correct is that the P-38 did shoot down more Japanese aircraft than any other USAAF plane with 1,857, with the P-40 running a close second at 1,633.5.

Even though the F6F did not start reaching Naval and Marine units in the Pacific until late 1943, when it did it came in prodigious numbers with the Naval carrier forces and Marine land based units concentrating on the destruction of both the Japanese Naval and Army Air Forces in that theater.  In the Battle of the Marianas, on June 11, 1944, Hellcats shot down 70 Japanese aircraft, and 6 days later on the 19th of June, they shot down another 354 enemy planes in "The Great Marianas Turkey Shoot".  In two days the F6F destroyed 23% of what it took the P-38 all of the conflict in the Pacific to do.  The F6F Hellcat has been somewhat forgotten and overlooked considering it was the top US fighter in the Pacific, and second only to the P-51 Mustang for total victories in the war.  The F4U Corsair, another Marine and Navy fighter, and the second place finisher in the destruction of Japanese warplanes in air to air combat, was used more by the US Marines than the Navy and for the most part operated from land bases in the Pacific and did not have the opportunities that the F6F had.

Also note the 138 victories by the Douglas SBD Dauntless.  In reading the 1942 book "Queen of the Flattops" by Stanley Johnston, which is the story of the original USS Lexington on her final cruise into the south Pacific and her eventual loss at the Battle of the Coral Sea, the SBD's on that cruise were very active in engaging enemy aircraft of all types in air-to-air combat during combat and scouting missions, including the Japanese Zero.  In the final air battle defending the ship, SBD's were launched along with the F4F Wildcats to defend the ship as the low altitude air defense screen.  At the end of the battle Ensign John Leppla, a SBD Scout Bomber Pilot, was credited with 7 kills along with his gunner, which was more than any of the fighter pilots had at the time on the USS Lexington.