Go on. Guess. Or, if you don't feel like guessing, read on to see the shipment figures for Final Fantasy XIII Square Enix released overnight.
With two million units shipped in Japan since the game's release there in December and three million sent to stores in the West for its release here this week, that gets us to five million. Oh, and in doing so, gets the entire series to 96 million.
Of course, that's five million shipped, not sold, but at this stage you'd have to imagine those two numbers are pretty close.