Daley Thompsons Olympic Challenge (PC)
Get yourself into the high score table then type in "HINGSEN-J" (Use the "-" on the numeric keypad). Press the DEL key and and the legend "DEMO!!!" should appear on the top of the screen. Now type "-J" And press the DEL key again and "MEGA-DEMO" should appear. Now press a function key and you've got 3 Bottles of Lucozade to boot!