When it comes to movie deaths, less is almost always more. Whilst seeing feral zombies tearing someone's guts out whilst they're still alive might scratch a sadistic itch - and there's nothing like watching an alien parasite bust its way though someone's sternum to get the blood pumping - it's the nuanced, cleverly concealed moments of fate that are the ones that stick with you. A little bit of mystery with your eye gouging goes a long way, after all.
It's true that the scariest deaths are the ones you don't see coming, and I mean that quite literally, since characters kicking the bucket off-screen usually have a far worse time than those that we see. Whether it's too visceral to actually play out or if the impact lies in imagining what grisly events could have transpired, there's an alarming amount of fictional people that meet their end where audiences cannot go.
If you were planning on sleeping tonight, then don't bother. These examples only further demonstrate quite how far we've strayed from god's light, and that you don't need to see to believe when it comes to just how nasty the human experience can get.