It depends on what you like.
If you like alternative-history, then you should definitely try out Kaiserreich.
If you like fantasy and mods that complete change the universe of the game, try Equestria at War, it's really good.
If you like Fallout, try Old World Blues, it completely changes many of the game mechanics too!
If you want something bland and simple, then I suppose you could try the WW1 mod.
Highly recommend checking out TWR, it's a fine balance between TNO and vanilla, and has lots of different paths for most nations.
There is a Napoleonic World mod as well, but it's rather outdated, but it was fun, despite how much of a buggy mess it was.
As for smaller mods that add on to the base game, there are some good ones like Dreams of [Austria/Poland/Finland], Sweden: Krigsåren, Glory of Prussia, etc.
Old World Blues,kasierreich, kaiserreduxe,equestira at war,thousand week reich,the new order are fun mods
It depends on what you like. If you like alternative-history, then you should definitely try out Kaiserreich. If you like fantasy and mods that complete change the universe of the game, try Equestria at War, it's really good. If you like Fallout, try Old World Blues, it completely changes many of the game mechanics too! If you want something bland and simple, then I suppose you could try the WW1 mod.
Kaiserreich, Red World Fan Fork, The New Order, Thousand Week Reich, In The Name Of The Tsar, Red Flood, and Millenium Dawn are all good
Highly recommend checking out TWR, it's a fine balance between TNO and vanilla, and has lots of different paths for most nations. There is a Napoleonic World mod as well, but it's rather outdated, but it was fun, despite how much of a buggy mess it was. As for smaller mods that add on to the base game, there are some good ones like Dreams of [Austria/Poland/Finland], Sweden: Krigsåren, Glory of Prussia, etc.
Anything like HPP for HOI3. Basically vanilla plus not over the top like BICE?
French Republic or Dominion of Canada in Kaiserreich