I've had fun with the netherlands (made from holland) and majaphut, along with bihar and denmark.
I love playing weaker countries and forming major nations with them. Some of my favorites have been Pskov, Saruhan, Papal States and Hesse.
Always loved the idea of playing gods represantative, but conquering more than a small european powerbase and Jerusalem just doesn't feel right.Papal States
I hated them in EU1/2 since they always became the BWB
Papal States
EU1/EU2 - Muscovy - "it all belongs to mother Russia" I still get a good laugh when I remember their 2 best generals January and February in action but since attrition is not as big a factor in EU3 and when the game was first released you needed QFTNW just to fight kazan and sibir