Both Europa Universalis and Crusader kings are fantastic grand strategy games. In Crusader kings 2 you are playing to enhance your house rather than having the greatest country or the most amount of provinces. You get score by family prestige and piety.
In Europa Universalis you are competing as a Nation, not as a house or family. You control a nation, rather than a family. You get score by technology, income, trade, colonization etc. rather than having to trifle with that person or that sister or that daughter or that matrineal marriage.