Let us start by choosing aircraft for a war in September 1939.
Fighter: Spitfire I (Bf 109E is the only obvious alternative)
Long range fighter, fighter bomber, and night fighter: Bf 110C (also reconnaissance)
Dive bomber: Ju 87 (Any votes for the Skua as a land based aircraft?)
Medium bomber: Ju 88A-1, LeO 451, Wellington or He-111H
Heavy Bomber: B-17B (in production from June 1939)
Shipboard fighter: Mitsubishi A5M4 (The first Brewster Buffalo will arrive in a month or two)
Shipboard torpedo bomber: Fairey Swordfish (I am probably being influenced by the radar that is not yet available)
Transport: Douglas DC-3
Flying boat: Dornier Do-24 (equal to the Catalina and better than most others on rough water)
One murky issue is whether we deploy the Mitsubishi G3M2 as a land based torpedo bomber or whether we hang the same torpedo from one of the medium bombers that had not yet dropped a torpedo. Similarly, do we have the G3M2 or the Lockheed Hudson just for over the water reconnaissance?
By 1945, the aircraft look slightly different
Fighter: Me 262 (by May 45, this is the most mature design for a jet)
Long range fighter, fighter bomber P-47N
Night fighter: P-61 or Tigercat
Reconnaissance / light bomber Arado 234
Medium bomber: Mosquito (by night) or A-26
Heavy bomber: B-29
Shipboard fighter: F4U4
Shipboard bomber: Aichi B7A
Transport: We are still probably using the C-47 but there are many new designs with advantages. The C-54, Ju 290 and Lockheed Constellation could obviously go further. The Arado Ar 232 and the Ju-252 could be loaded more easily.