I enjoy this topic very much, Glenn! In my own experience, crusades are the spice of the game. They lend colour and (if you're the historical type, like me) give you something to strive for. For example, if I'm playing as one of the Frankish nations (France, England, HRE, Sicily), I usually launch a crusade to Palestine before 1099, which is a challenge, to say the least, when you're still struggling to get your economy off the ground. (Of course, it's not always feasible.) One thing I can't stand, though, is to see a game reach 1205 (or 1230, or 1300, for that matter) with no crusades launched. If I am playing the Germans or Danes, I go East to establish the Baltic Orders. (It's always fun to send your crusades overland to see what random troops they gather to the cause.) Finally, it's never too soon to crusade as the Spanish, though it takes some self-restraint, I think, not to end up in Tunisia by 1090!