This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Rise of the Planet of the Apes
Yeah, Hunsiker was a jerk, but consider this: Imagine being chased by a vicious chimpanzee hellbent on killing you for being angry your car's been smashed up. Or worse, being the poor bastard getting beaten to death by a dozen or so angry apes. At least Caesar steps in to save the latter before it's lethal, putting Rodney in a cell for his own protection.
Koba himself. Out of all the apes, he's the most horribly scarred and demonic looking.
Caesar's first few moments in the primate center. Locked in a small cage, at the mercy of a threatening human "overseer" whom he can understand, and surrounded on all sides by angry chimps screaming and thrashing around violently.
Caesar's Big "NO!" will send chills down your spine.
The end credits show an infected Hunsiker going off to his job as a pilot, and a graphic displaying the subsequent spread of the virus across international flight routes...
A deleted scene that came to fruition in the sequels: a lone ape walks through the forest when he finds a hunterís discarded shotgun. After a few seconds of the ape treating the gun like a normal ape would (even trying to eat a shell), the ape quickly figures it out, loads the gun, cocks it, aims at the screen, and...BANG!!