I'll be voting for the P-39 and the B-25, both widely used by many of the Allied air forces.
If a 3rd were to be created....
G.55 is nice, but it was very rare.
He 111 will be a hanger queen.... Trust me. Good for the EWA and scenarios though. Ju 88 is better.
Brewster should be added, if for no other reason than to reward our Finn members for contributing so much to the game. They have certainly earned it. I would be quite happy to see it.
Ki-44 would be well used, but the Ki-43 is under-gunned and thus would be a hanger queen after the initial novelty wears off. Ki-45 is inferior to the 110G-2, and would not get a lot of use.
Pe-2 and Tu-2 would get less use than the B-25. Would be great additions tho, adding diversity to the plane set.
Yak-3 would be a nice addition, but was not as widely used as the P-39. Besides, the P-39 does add a VVS fighter.
A-26 would be a terrific addition, but the B-25 had a far greater impact on the war.
Me 410.... Doesn't fill any real need.
My regards,
Widewing