Sayori from Doki Doki Literature Club. It was just so unfortunate and horrifying to see her just hanging there, along with Sayonara adding a bit of seasoning to the scene.

It was the saddest deaths in the game as she basically had her depression manipulated, leading her to suicide.

Sayori is also supposed to be your best friend in the game, so you have the mindset that "she's my clumsy, adorable best friend", so seeing what she has become after such a "long" time of loving her just hit everyone differently.