What seems to be missing from most people's list so far is anything from the Soviet airforce! AH currently has no Russian heavy bombers, and virtually no early war fighters. Two other things would be valuable additions not only for scenarios and the CT, but also for the MA: a) ANY Russian tank, and b) a Stuka tankbuster.
Out of all the major air forces, the Soviet is probably the least developed in terms of plane set. It's just that there are always so many LA7s in the air that it seems like there are a lot of Soviet planes in AH.
[ah, Halo beat me to it, good list]
I would love all the bombers mentioned, although the Betty, an early war Luftwaffe bomber, and the Blenheim are probably the key additions. But it's not much good adding more bombers until they get the existing bomber damage modelling fixed.
