I wish I was exaggerating when I say that I've spent upwards of 4k hours on EUIII/CKII, what that time was spent on, where it happened and how I managed it still confuse me. The immensely replayable single player aside it isn't uncommon for myself and the friends I play this with to spend a year, a whole year, playing a single multiplayer campaign.
These games are gifts from a rare confluence of understanding and intuition about what separates a good game from a great game, one that is even less common to see in a genre that features solid multiplayer.
Sigh... I wanted to get into this but I need a new video card. Guess it's not happening :/