We need a lot more Russian/Soviet aircraft, but not always the obvious choices.
I'd like to suggest:
Tu-22M3
Su-15
Su-7BM
Tu-95
MiG-23/27
MiG-31
Mi-26
But any additional Russian aircraft or helicopters would be nice, even the flashy ones that everyone loves. But let's not forget the less glamorous work horses. They're fun too.