The more I read this thread, the more I start to feel bad for not picking my favorite game as "the best" game. Ultimately there are (a few) things I would change about SMAC, so I feel like I can't choose it over a game I see as perfect for the title of "Best".

But I still feel bad, so I'm mentioning SMAC and pointing out that it's still one of the greatest games ever made. Also to be sure I don't drop my SMAC/X-Com post ratio down below 2.5%.