9. The Tracking Droid - Star Wars: Episode I - The Phantom Menace
When fleeing Naboo in The Phantom Menace, Qui-Gon Jinn, Obi-Wan Kenobi, Queen Amidala, and their gang all end up on the desert planet of Tatooine.
Here, they come across a young boy named Anakin, who just so happens to be the prophesised child who will one day bring balance to the Force.
They're not the only interlopers on Little Ani's homeworld. The good guys are being hunted down by about one-third of Darth Maul's entire screen time.
The horned Sith lands on the barren world and dispatches a group of tracking droids to find his prey. The audience is left to assume that they were successful, as they never actually see the robots at work.
Or do they?
After Anakin wins his freedom in a pod race, Qui-Gon is seen talking to his former owner Watto. In the background of this shot, you can see one of Maul's droids.
This is a neat little detail that really didn't have to be included in the scene. It does a great job of tying the Tatooine portion of the film together.