Star Wars Episode 1: The Phantom Menace - I Thought Darth Maul's Lightsaber Had Two Blades!
In the final shot of the desert battle, you see the Queen's ship lifting into the sky. However, if you look at Darth Maul's lightsaber, the end that wasn't activated has a flat edge. Therefore, no blade should be able to come out of it, right?!?!?! This weapon was obviously a different prop then what's seen at the end of the movie. Note: this flub is very easy to see if you don't know about it, especially in the full-frame version, as the screen shows more of Maul than the widescreen. Plus, the sun's reflecting off the end of the lightsaber.