This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Snow White and the Huntsman
Queen Ravenna herself. Holy hell. She's genuinely creepy as hell at times and one sequence involving her standing in the fire causing her flesh to be burned off is disturbing. It's all somewhat hampered by Charlize Theron's acting, though. Though reaction to Charlize Theron in the role would indicate a lot of Nightmare Fetishists.
The dark forest itself.
The sequence of Ravenna literally sucking the youth out of a young peasant girl, who ages from twenty to seventy in seconds while held up by the throat. Worse, she's alive afterward, letting a horrified Snow see her in her cell and amazed it's the same woman.