I really can’t honestly vote for the allies as my favorites. Russia is more or less restricted to building land forces. Britain is immediately put on the defensive as she loses almost everything she has and can’t effectively get it back until the US intervenes, and the US takes ages to get forces put anywhere useful, at least in sufficient amounts.
I’ve got to go Germany, it has a lot of power right from the start, it has enough income to build a fleet or an airforce or ground units, whatever it needs at the time, and it can go out across the board (Africa, Russia), at least until the US show up.
Plus I just like taunting my friends by saying “I hope you like the taste of beer because it’s coming to a tap near you.”
None of that vodka or tea crap :-D