Holland->Netherlands is imo the best country eu4 has to offer because they combine two things that rarely come together:
1) A great challenge of a minor rising against major empires
2) Historicity, flavour and enormous potential
And also: Netherlands allow on trying literally everything eu4 has to offer. I am halfway through Holland->Netherlands game and during these 200 years I have experienced:
*Dramatic wars on land and sea against Burgundy, Spain, Portugal, England, France, Hansa, Denmark, Sweden, Austria, Bohemia, Milan, Qing, Vijanaygar, Mutapa, Mali, Ottomans (!), Aztecs, half of HRE minors and some more
*My army and navy was fighting everywhere - in the jungles of Mexico, in the middle of Louisiana, in far north of Alaska, in Caribbean bays, in the heart of HRE and in the Iberian mountains, in the English Channel and Mediterranean Sea, in the Baltic and Bohemia, Italy and North Africa, over trade companies in Africa and in savannahs of Mutapa, in the Indian Ocean and jungles of Borneo, in the Australia and Taiwan
*In fact, thanks to awesome exploration system of El Dorado, I have established contact with Japan by the half of 16th century, and in this era I have circumnavigated the world
*I had a lot of historical events
*I have participated in the League Wars, in the Reformation, in HRE wars over the emperor, and it looks like I'm going to be in the middle of revolutionary mess