1. Apocalypse Now (1979)
The making of this war epic felt like a battlefield in itself considering the incidents that took place during filming. From severe weather destroying sets in the Philippines to lead actor Martin Sheen suffering a heart attack, director Francis Ford Coppola described the shoot as one filled with "chaos and insanity." The delays caused tensions to rise as the film’s budget skyrocketed to unprecedented levels. Coppola even mortgaged his own home to keep the project afloat, leading to immense personal and professional stress. Adding to the turmoil was actor Marlon Brando’s erratic behaviour and lack of preparation, which forced Coppola to improvise critical scenes. Despite these challenges, the film is now hailed as one of the greatest war movies ever made.