There is a scene in which Hoffman’s unforgettable ‘Ratso’ Rizzo is walking our midnight cowboy Joe Buck (played by a young Jon Voight) through the streets of New York. He’s coaching him about becoming a successful stud and gigolo, and while crossing a street nearly gets hit by a yellow cab. Hoffman beats the hood with his fist and shouts, “I’m walkin’ here!” in his unique New York parlance, yhen quickly retorts to Voight, “Actually, that ain’t a bad way to pick up insurance y’know.”

“I’m walkin’ here.” is often cited as one of the world’s best movie quotes. It’s usually thought of as an improvised line, which Hoffman has claimed. And he is certainly more than capable of this kind of fleshed-out character portrayal. But producer Jermoe Hellman has always maintained that it was in the script. The romantic film buff in me likes to believe the former, but I guess we may never really know.

Dr. Strangelove, Or: How I Learned To Stop Worrying And Love The Bomb: Dr. Strangelove’s sporadic involuntary Nazi salute(Stanley Kubrick, 1964)

Apparently, so many of Sellers’ lines in Dr. Strangelove were improvised that he is often cited as an uncredited co-writer. And it is considered a study of retro-scripting, ie. when ad-libbed lines are later written into the final script. So, it’s difficult to know which one to pick, but perhaps the most ingenious and intuitive is when his title character performs sudden involuntary Nazi salutes in the company of the US military (Sellers plays three characters in total).