Ok, I'm planning to start a new Hearts of Iron 4 play through, but this time I'll be using my favorite mod for the game: Kaiserreich. Now, there's a lot of lore to this mod, so I'm doing this post to explain it before we get started.
Basically the starting point where the Kaiserreich timeline split off from our own is that in this world, Germany won the First World War which is known by it's German name the "Weltkrieg" in the Kaiserreich world. This resulted in both Britain and France having Syndicalist revolutions. (Syndicalism being more or less the Kaiserreich version of communism.) In Russia on the other hand, the White movement managed to crush the Bolsheviks, and Russia remains a (highly unstable) republic.
Because of Germany's victory in the Weltkrieg, the Treaty of Versailles never happened, so the German people do not feel humiliated resulting in the Nazis never rising to power. Instead Kaiser Wilhelm II remains the Emperor of the German Empire, although he is facing challenges, both from vengeful Syndicalists in Britain and France, and from protesters in Germany who want reform.
Italy meanwhile, is split between the highly conservative and Catholic Italian Federation in the North, and the syndicalist Socialist Republic of Italy in the South, and many predict that the Italian Peninsula is a ticking time bomb.
The British Royal Family has managed to escape to Canada, where they are plotting to liberate Britain, along with their Nationalist French allies in exile in Algeria.
India is split between the Loyalist Dominion of India in the west, the syndicalist Bharatiya Commune in the east, and in the south there is the Princely Federation, a loose alliance of various anti-Colonialist rajahs who want to cleanse India of both syndicalism and western influence.
Oh, and Australia and New Zealand are united as the Australasian Confederation.
But the most important change from our timeline is in America. The US economy has been in decline ever since the crash of 1929, and this has resulted in radical extremist movements arising both on the left and on the right. That, combined with a Syndicalist Mexico on the border, is making North America a highly unstable region. The year is now 1936, and things look likely to get very dangerous very quickly...
So now that I've explained most of the backstory, here's a list of countries I think would be interesting to play:
Germany
Russia
Canada
America
Syndicalist Britain
Sweden
I'll let you decide which I'll do. Comment below which country you want to see.