Pong. Jesus, at least lie and say Super Mario Galaxy. But to Obama's credit, when McCain was asked the same question he answered "rolling a hoop down a dirt road with a stick", which, to the best of my knowledge, isn't even a video game. So the question remains: can we really trust a president that hasn't killed a hooker in Grand Theft Auto? The prosecution rests.
Geekologie Writer '08: Totally not afraid to kill hookers.
Hit the link to read a little interview with Obama with other, similar questions, like who gets to control the remote in his house (answer: HGTV).
Barack Obama: My Pop-Culture Favorites [entertainmentweekly]
Thanks Craig, you can be my running mate.