It seems to me like this one is the hardest for long strategy games to do well in. Most of the games that I've played, the last 10-15 minutes are a foregone conclusion.
Last 15 miutes a forgone conclusion, I just finished a Galactic Civ where the last half the game was a forgon conclution, I can't think of many that past the 1/3rd mark there have been 'natural' changes of who's winning (not caused by game changing random event.)
In advanced civilization, the boardgame (the ancient one, not the one from sid meier civilization) you got really awful events once you got some cities. The more cities, the more chances you get things like rebellion, flood, piracy, civil war (that one was nasty).
the game should be like "I don't create more cities/do more research/do dungeoning because i want but because I NEED it".
Players should be struggling for survival. I always like in civ4 when barbarians are really really active. And the armageddon counter in fall from heaven 2 is a really nice idea.