Psycho
Famous for that scene in the shower with the big Kitchen Devil, Psycho should also be remembered as the first film to feature a flushing toilet - according to trivia anoraks anyway.

Marion Crane (Janet Leigh) legs it with $40,000 that her boss asked her to deposit at the bank and stumbles across the motel with the least used guest book - The Bates Motel.

At the front desk is Norman Bates (Anthony Perkins) who seems to have an unnatural obsession with taxidermy and his mother.

Of course crime doesn't pay and Marion meets a particularly sticky end - Hitchcock used gallons of chocolate syrup instead of blood, as Norman ruins the shower curtain and Marion with the carving knife, all to the sound of screeching violins.

Psycho was remade by Gus Van Sant in 1998, but his opportunity to indulge in a vast chocolate-fest was scuppered by advances in film technology (i.e. it was in colour).