Crusader Kings is an excellent game that not only covers the strategic level, but also the personal level. Not only do you control a nation, but you are also in control of the leader. It's not a traditional empire-building game. It focuses on building your dynasty's prestige (and piety), rather than territory. There are three levels of nations: Kingdoms, duchies, and counties. You can play as any Christian character holding land, assuming they rule a monarchy. Traits, affecting stats such as Health, Martial, Diplomacy, Stewardship, and Intrigue will occur by means of events. These in turn affect how you rule. All nations have courts. They are made up of the Marshal, Chancellor, Steward, Spy Master, Diocese Bishop, and courtiers. Courtiers can fill any position in your court, and you can also take actions such as vassalize them and give them land. However, only certain people can fill certain positions. For example, a Marshal needs to be a male with a martial education, and a Diocese Bishop a male with a theological education. Vassals are another important aspects. In Crusader Kings, you can only rule over so many provinces by yourself before you start to take in a penalty in direct income from your demense. This is based on the combined Intrigue of you and your Spy Master. The solution to this is ceding land to vassals. Vassals have a "Loyalty Rating" - from 0 (Disloyalty Incarnate) to 100 (Very Loyal). Loyalty is also reflected in court members, who may plot against you if it is low. Loyalty is raised or lowered in a number of fashions: It comes on a monthly basis, or can be raised or lowered by events. On the monthly basis, factors such as traits, your prestige, diplomacy rating, and family ties make up the total for the month. If it gets around or below 35, then bad events start to happen - vassal disloyalty. This can lead to realm duress, a civil war between you and your loyal vassals and rebellious ones. Realm duress is terrible: I've seen one of the biggest factions, the Kingdom of Germany, be thrown into a horrible war by it, and to come out at -729 prestige, their leader killed in battle with no successor, and lost most of their vassals. Of course, if you are a vassal, you can always declare independence, however it may lead to war. One of the best times to do this is when your throne is inherited: You, now playing as the new leader of your nation, have the option to recognize your new liege, or break away. In my experiences, this usually comes out with a 70% success rate and is best done when your liege is fighting a major war. There are many other features that I have glossed over, but this is the gist of the game. There are things such as marriage, the Papacy, Crusades, and more, but I don't think I have enough time to write a 6,000 word review.
Edit: You can get Crusader Kings and it's expansion Deus Vult in a bundle on
GamersGate for $20.