My order of what I'd like to see:
Yak-1 or LaGG-3 (For Eastern Front mid-war, where there is otherwise large gap for Soviets; Yak-1 was more produced)
B6N (Most-produced Japanese torpedo bomber, taking over for the early-war B5N)
D4Y (Most-produced Japanese dive bomber, taking over for early-war D3A)
Pe-2 (Most-produced Soviet attack plane other than Il-2, for Eastern Front)
TBD (Important for Battle of Coral Sea and Midway)
Beaufighter (Multi-role, would add a lot of flavor to events)