These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Once Upon A Time In The West
Alas, Poor Villain: Morton had the desperate goal of seeing the blue ocean of the Pacific before he succumbed to his fatal disease, instead dies slowly face down in a mud puddle while he imagines to hear the ocean.
Complete Monster: Frank. Years ago, he killed off Harmonica's brother in probably the most sadistic way possible, and now he goes and kills off a farming family, including their youngest son. Then he advances on the widow.
Morton: Tell me, was it necessary that you kill all of them? I only told you to scare them.
Frank: People scare better when they're dying.
Moral Event Horizon: The way Frank killed Harmonica's brother. Forcing a little boy to support his fully-grown brother so that he doesn't die by hanging is one of the worst acts of cruelty a Leone villain has ever done.
Frank killing off Jill's nice new family. Especially because she doesn't know, and is looking forward to her new life. Poor Jill is understandably horrified when she arrives.
The death of Cheyenne. That is all.
Hey, Harmonica. When they do you in, pray it's somebody who knows where to shoot.