How addicting is Civilization IV and in what ways?

Title sums my question up. How addicting is Civilization IV and in what ways? Should i buy it instead of Fallout 3, End War, or even Company of Heroes?How addicting is Civilization IV and in what ways?
I love Civ IV! It is fun because the source of the outcome is always going to be different. It is not your "same ol, play it through" type game. You get to decide how you want to play the game. You can play with allies, be a war machine, etc. Civ IV makes you think while playing!! Not only abou this turn, but what your plan is for the next several turns!How addicting is Civilization IV and in what ways?
I bought it, but can't play because of vista... If anyone knows how to get around this, please email me!!!!!





Any how, I have played ALL the others, and if this turns out to be as good!!!



You will have NO LIFE after playing for the first time... It is VERY addicting!