The iconic scene in 'The Godfather' where the horse's head is placed in the bed was so realistic that the actor's scream was genuine.
In 'The Departed,' Jack Nicholson's character was based on real-life Boston mobster Whitey Bulger, adding authenticity to the film's portrayal of crime.
During the filming of 'Pulp Fiction,' John Travolta's dance scene was improvised, and Uma Thurman's overdose scene was shot in one take.
Heath Ledger's intense portrayal of the Joker in 'The Dark Knight' led to rumors of his method acting causing sleepless nights on set.
The famous diner scene in 'Heat' featuring Robert De Niro and Al Pacino was the first time these two acting legends appeared on screen together.
In 'Goodfellas,' Joe Pesci's improvised 'Funny how?' scene was based on a real-life encounter he had, adding an unexpected authenticity to the film.