Deus Ex Machina on the Commodore 64, definitely. Fantastic soundtrack in an unashamedly Shakespearian vein, wonderful cast including Jon Pertwee, Frankie Howerd and Ian Dury, bizarrely esoteric gameplay. Now something of a cult classic, I understand.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'