Luc Besson's Lucy touts one of the more infamous endings of any film from the last decade, when Lucy (Scarlett Johansson) finally unlocks 100% of her brain capacity, causing her to undergo an epic transformation.
She hits 100% just as drug kingpin Mr. Jang (Choi Min-sik) is about to shoot her in the head, causing her to suddenly disappear into thin air, much to the amazement of everyone in the room.
At 100%, Lucy has transcended her physical form and entered the spacetime continuum, where she now possesses the ability to be everywhere all at once, while leaving behind a USB stick containing all of her accrued knowledge to help humanity.
Though Lucy doesn't "turn into a USB stick" as many flippantly suggest, the ending isn't really much less ridiculous than that.
The many viewers hoping to see Lucy go full-on Super Saiyan mode at the end were surely left disappointed that she just... disappeared and the film then hastily ended totally out of nowhere.