Tell us about that one game. If you had no other games, you could only pick one, which one would it be? Tell us why.
My head burns when I try to answer this question, if I really have to choose or die I'll probably just randomly mention one of the last three games I played... But If I have to choose the actual one I'll think for a long time without giving a honest answer. (Don't want to bother now)
I think it must have massive replayability though, it's really great to play story games the first/second/third time, but they start to become boring fast.