Honorable Mentions

>Stainless Steel Historical Improvement Project (SSHIP)
An expansion of the original Stainless Steel SSHIP tries to "EB2" the base mod making it more complicated, slower, in depth, and more accurate. Faction names, units, and buildings are renamed into the correct localized language. A new map and more period accurate music is added and a number of scripts create a more difficult and immersive experience
https://www.moddb.com/mods/sship

>Broken Crescent
Focusing on the Middle East from Constantinople to India depicts the rise of the Mongols and the failure of the Crusades. Buff and Shine provides bugfixes for the original.
https://www.moddb.com/mods/buff-and-shine-broken-crescent-22

>JLMP Vanilla Kingdoms
A very simple mod that just adds factions and mechanics from the Kingdoms expasion to the base game
https://www.moddb.com/mods/jlmps-vanilla-kingdoms-2022

>Roar of Conquest
A continuation of Stainless Steel which tries to provide bugfixes, balance, and new units
https://www.moddb.com/mods/roar-of-conquest

>Bulat Steel
A continuation of Stainless Steel which tries to provide bugfixes, balance, and new units. This one adds navigable rivers
https://www.moddb.com/mods/bulat-steel

There are many more mods that I'm just not very familiar with but that's where you can post and tell us all about them!

What's your favorite mod, anon?