Thinking back on it, both the Civ I and Civ II games got more of my time individually than Col ever did. As previously mentioned in this thread, Col had a more restricted game in many respects and so there was less interest for me to play many new games with new goals, countries, worlds, etc. On the other hand, the trading/resource component of Col was always more interesting than Civ I/II.
So I answered the Picard/Kirk way. Without that option I would probably go with Civ on the basis of the time I spent with it, but at the same time I wouldn't have wanted to not have ever played Col.
So the lastability is the remaining concern I have with the upcoming new Col. Civ IV opened up so much with the modability and game play styles, I think that the goal posts for Col II will be so much higher. After the fun of the new graphics and the nostalgia of the trading/resouce from the old game, will the game prove the test of time for me? While there is modability, will the nature of the Col style of game play work as well with the modding?