Signs (2002)
Spoiler alert! If you’ve seen the classic movie Signs by acclaimed filmmaker M. Night Shyamalan, you know aliens are revealed at the end. We do get a quick view of them, very briefly at the beginning of the movie. Understandably, this quick glimpse is what gets this scene on the most-paused list!
The fact that it’s not the greatest quality makes it all the more mysterious. It was actually intentionally done by producers, they worked hard to create a sense of fear and uncertainty in the viewer. You create what you think it looks like in your imagination, and then you finally get to see what it looks like at the end.