Super Mario
From Tardis Wiki, the free Doctor Who reference
Super Mario, or simply Mario, was the eponymous protagonist of the Super Mario Bros video game. (PROSE: Halflife, TV: Sky)
The virtual Twelfth Doctor likened the inhabitants of the Shadow World finding out they were a simulation and committing suicide as a result to a hypothetical scenario in which "Super Mario realises he's inside a video game". (TV: Extremis)