“Yippee-ki-yay, mother***!”
The scene: John McClane talks to villain Hans Gruber on the radio. In this scene, Gruber asks if he’s just an American that has seen too many cowboy movies, to which McClane replies, “Yippee-ki-yay, mother****!” As it turns out, that line was written differently in the script.
The screenwriter had written “Yippee-ki-yay, a***hole,” but Willis changed it during the scene to amuse the film crew. Neither thought the line would make it into the movie, considering this was 1988, and such open profanity in films wasn’t easy to get past movie studios. Nevertheless, this scene became one of cinema history’s most famous lines.
Reservoir Dogs
"You hear that?"
The scene: Mr. Blonde is dancing and cuts off the policeman's ear. Reservoir Dogs is a 1992 classic, and with so many iconic scenes, it's hard to pick a favorite. One of those is the scene where Mr. Blonde (Michael Madsen) starts dancing to "Stuck in the Middle with You," the famous Steelers song that became the flag song of the film.
During the scene, he suddenly cuts off the cop's ear, holds it up, and says, "You hear that?" In the original script, the scene described Madsen dancing and then setting the cop on fire after cutting the ear, but Madsen thought it would be much funnier to add that ironic little line in between, and Tarantino loved it.
Avengers: Infinity War
"I don't want to go."
The scene: Peter Parker is in the arms of Tony Stark and tells him he is afraid to stay on Earth. This movie boasts A-list actors, a solid script, and mind-blowing special effects, and it became one of MCU's most beloved Avengers films.
That heartbreaking scene where Peter Parker (Tom Holland) says to Tony Stark (Robert Downey Jr.), "I don't want to go," is cinematic magic. But that wasn't in the script! Tom Holland was only told to act like he didn't want to stay on Earth, but he decided to throw in that line, and it couldn't have turned out better.
Clueless
"I'm totally buggin' myself."
The scene: Josh is talking to Murray and Travis at a wedding while eating cake. At the end of the film, Josh, Murray, and Travis are all sitting together with their respective girlfriends at a wedding.
When suddenly, Josh, as he's shoving a huge piece of cake in his mouth, says, "I’m buggin’ myself,” in response to his friends saying they were bugging out because their girls were already planning their weddings. The line was improvised entirely by Rudd and had the other guys laughing uncontrollably because of how he said it. It was all real!
The Princess Diaries
“Not you. I don’t even know you.”
The scene: Lilly is running down the street, trying to get Mia’s attention. In the scene where Lilly (Heather Matarazzo) is running down the street trying to get to her friend Mia (Anne Hathaway), she tries screaming out so Mia slows down.
But instead, some other guy turns around. To this, Matarazzo ad-libbed the funny comeback, “Not you, I don’t even know you.” As the actress said in a later interview, this was apparently the producer's suggestion, which, like the rest of the crew, just felt like a very close group of friends working together.