This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Human Centipede
The brief moment in the cage at night, when all three members of the centipede silently hold hands, may be as poignant as this movie gets.
Eventually, Jenny dies of the blood poisoning that has been worsening since the operation. In their current condition, they can't even speak to each other — Lindsay can do nothing but grip her hand until she goes.
Jenny sobbing, "I want my mom!" while the doctor gives her the anesthetic is one of the most effective parts of the movie.
Lindsay's reaction to her fate at the movie's end is so broken and pathetic that you might actually have an emotional response.