I change my mind:

Spain because of javelinmen spam armies. Those battles are lost through sheer boredom.

Aragon/Danes(nice challenge to play as) in early because of RK spamming royalty.

Germans because I suck at them.

Turks/GH/Novograd/Egypt because, like Spain they have tend to spend all their money on cheap spam units. Cavalry spam is ANNOYING especially with HA.

Huns because once a unit of their Elite Horse archers that joined an English Crusade single handedly routed one BI and routed my whole 6 star Byzantine army.