Apocalypse Now
Now, this is an extreme example of improvisation. Everyone knows the legendary Marlon Brando, though a huge talent, was notoriously troublesome to worth with on set. Brando took method acting very seriously, and enacted his characters’ quirks in his life. During his role as Colonel Kurtz in Apocalypse Now, he refused to learn his lines. Supposedly, he wore his script like a paper hat. At the end of it, he ended up improvising around 18 minutes of his dialogue.
Blade Runner
Of course, Harrison Ford became even more celebrated once he starred in Blade Runner. However, this incredible movie moment comes from the other star of Blade Runner, Rutger Hauer. In the final scene, Hauer stuck to the original Blade Runner script at first. Quickly, he deviated into what became the “tears of rain” speech. Yeah, there’s almost nothing more iconic from Blade Runner than that.