9. Darth Vader In The Phantom Menace
The prequel trilogy is more or less a Shakespearean tragedy, recounting the rise and fall from grace of Anakin Skywalker. Over the course of the three films we see the innocent and kind-hearted former slave boy transform into one of the greatest Jedi Knights the galaxy has ever known, before succumbing to the Dark Side. The warning signs were evident in Attack of the Clones, if slaughtering a whole village of Tusken Raiders is a sign for concern.
Of course, anyone familiar with the original Star Wars trilogy knew all too well what Anakin's fate had in store for him. But if anyone was still in doubt, George Lucas included an ominous piece of foreshadowing in The Phantom Menace. It takes a special kind of fan to sit through the entire credit sequence of a film like Star Wars, but one such individual discovered Lucas' biggest nod to the original trilogy.
Long before easter egg credit scenes were a thing in Marvel, Lucas added in a little teaser right at the end of the Phantom Menace. Just as the score cuts out, the unmistakable sound of Darth Vader inhaling can be heard.