Bethesda Softworks Inside the Vault Q&A

Bethesda's latest "Inside the Vault" feature profiles Mike Dulany, who did QA on The Elder Scrolls IV: Oblivion and is now a programmer on Fallout 3.
What would you say is your personal favorite game of all time?
I think it would have to be one of the Smash Brothers titles; the sheer number of hours of enjoyment I've received from multiplayer matches with friends dwarfs any other game I've played. I still play Melee with a level designer here at Bethesda very frequently, to the point that he stores his GameCube console in my cube. Which leads us to.