Interesting that the current example is Skyrim. Which is really just the classical D+D game with great graphics.
Personally I found the more impressive growth of games to be the widespread acceptance of gaming with Wii/Kinect and mobile gaming.
I assume Skyrim is the example because of how huge it is. Not counting some procedurally-generated games, I can't think of any bigger single-player games.
i know what you mean, even grandmas plays those games now