Nothing like recruiting a bunch of peasants, feeding them with bread and butter, and turning them into a formidable army capable of subjugating the civilized world.
I love this game, it contains a healthy mix of RPG elements, simple but brutal combat, lots of different unit types, equipment, horses, and even a bit of political intrigue.
There's always something to do, this game is highly addictive, you can always find someone to fight, a castle to siege, land to develop and ladies to woo.
I can't recommend this game enough. You can always mod it if you don't like something about it, or try the sequel.