For most of the examples on this list, a character makes a mistake that improves a scene with ad libbed dialogue, a forgotten line, or the mishandling of a prop. When it comes to 1977's Star Wars, the most infamous blooper has got to be the time a Stormtrooper slammed his head into an opening door.
This is one of those scenes every fan of the franchise knows, but probably missed the first time they watched the movie. After all, it happens in a fraction of a second and the main point of focus is more towards the center of the screen when it happened.
Regardless, it happened over 40 years ago and everyone knows about it, which is why this gaff remains one of the best of the series. It may have been a random Stormtrooper in a simple scene, but it set a standard George Lucas felt he needed to clarify years later.
In the 1997 Special Edition remaster of the film, the director added an audible "Bonk" sound and even recreated the scene in Attack of the Clones. As Jango Fett was walking into his ship, he bonked his head on the opening door in exactly the same way, which solidified the trait in Stormtroopers, his clones, having originated right there at the source.
Jonathan is a graphic artist, illustrator, writer, and game designer. Jonathan retired from the U.S. Army in 2017 and enjoys researching and writing about history, science, theology, and many other subjects. He writes for ScreenRant, CBR, NerdBastards, Listverse, Ranker, WhatCulture, and many other sites online. You can check out his latest on Twitter: @TalkingBull or on his blog: jonathanhkantor.com