Ever since picking up Paradox's Europa Universalis I I have been addicted to their games and have played less and less games by other developers. EU II, Hearts of Iron and Victoria are all marvelous. This game has tended to get overlooked. I think every paradox game has unique qualities, EU has amazing world depth, you play with and explore, conquer and engage in relations with hundreds of nations. HoI has a terrific focus on building diverse armies of multiple military units, making it a grand strategy WWII game of unequaled depth. The unique selling point of Crusader Kings is its focus on building a dynasty in Medieval Europe. Whilst military activity is abundant the real fun in this game is breeding, building a ruling family, and managing relations with your vassals or your liege. You take on the role of a King, Duke or Count and your rule can be threatened as much by your character being excommunicated or going insane as by invasion from a foreign power. You can rise from a lowly count on the Shetland Islands to a great emperor ruling most of Europe but you can also tear your hair out as misfortune takes you in the opposite direction. Although this is my favourite Paradox title, on balance I would recommend you try EU II or any of the Hearts of Iron titles first to see if Paradox's unique approach to historical simulation is for you.