Best European Nations to Play?

I am searching for a new nation to try in Europe. I have played France, England into the Angevin Kingdom and Byzantium to completion. I am not an achievement hunter although I do still play in Ironman and I love to play as countries with beautiful colors or great mission trees, out of my 3 I’ve completed I will have to say Byzantium is the funnest yet hardest and even tho I’ve done it twice and am also doing a 3rd try I still cannot push to form the Roman Empire.