Whether you started with a 2600 and a joystick in your hand, an N64 with a blistered palm or building your first PC in your teens, what is that one video game you've played at some point that to this day sits at the top of your list.
But yeah, my original playthrough - great puzzle game, then suddenly there was plot, and a huge plot twist, then the ending was crazy, then that song.... So freaking good.