LittleBigPlanet is the game that convinced me to start gaming. This introduction perfectly sets the tone for the game, the universe, and the possibilities.
For example, it was 30 years after the invention of film that someone first tried telling stories with it — before that, film was mainly used as a demonstration of the technology itself, and had little meaning to the average person. It was only after a technology-medium fit appeared that it became compelling and its promise was realized.