I may be an outlyer here, but I'd really like a series of proper Boxer Rebellion troops here. Whatever has been produced so far could really be improved massively.

There are also some key WW1 sets that are very much missing, in particular Romanians and Bulgarians. Greeks would also be nice, in particular the Evzones that fought so bravely in WW1.

2nd/3rd century Roman legions.

Fill the gap between the familiar 1st century legionaries and the almost Byzantine "late" Roman sets.

Would not necessarily require new "Barbarian" types, as these legions spent as much time fighting each other for their respective nominees to the purple.

Though we still need some decent Goth/Vandal/Frank era German infantry units.

Also support calls for Anglo-Indian wars of 19th century; native armies would make great figures.

Russo-Japanese war.