"I'll be back" — The Terminator (1984)

Arnold Schwarzenegger almost had this line rewritten to "I will be back" because he struggled with contractions in his Austrian accent. Director James Cameron insisted on the original phrasing — and the rest is pop-culture history. The line has been reprised, parodied, and referenced in hundreds of films, TV shows, and political speeches (including Schwarzenegger's own). It became so synonymous with Schwarzenegger that he used it in his 2003 gubernatorial victory speech.