For me, it's a tie between the Mongols, Huns, Koreans and Spanish.
Spanish are a force to be reckoned with on the water mostly due to their advanced cannon galleons.
The Huns make excellent opponents, and not having to build houses is a good bonus.
The Koreans are good for a defensive style play. Also, their siege weapons and war wagons are good weapons.
And finally, the Mongols. Excellent horse archers (a group of 15 unique units can basically take any unit down in one hit) and fast moving siege weapons.
What are yours?
Spanish are a force to be reckoned with on the water mostly due to their advanced cannon galleons.
The Huns make excellent opponents, and not having to build houses is a good bonus.
The Koreans are good for a defensive style play. Also, their siege weapons and war wagons are good weapons.
And finally, the Mongols. Excellent horse archers (a group of 15 unique units can basically take any unit down in one hit) and fast moving siege weapons.
What are yours?