I am in a mortuary being forced to watch the autopsy of a loved one. Nobody takes any notice of my begging to leave or my crying and screaming.
I am locked inside a coffin, in a silent grave, while a loved one decomposes beside me. Nobody can hear my attempts to get out or my crying and screaming.
In both cases, crying and screaming is how I wake up.
I have a couple of others...
Teeth dissolving or a related dental horror theme.
Dreaming that I'm dreaming and waking up in the dream on the morning of my English A-level to realise that it's all still to come - exams, results, uni, finals. That's always a great relief to wake up from and realise that it's not all still to come.
A killer has left a loved one for me to find after horrific things have been done to them - amputations, inverted eyelids, carvings, shaved bleeding heads, etc. With their terrified pain filled last look frozen in their staring eyes.
Running through a corridor with grey carpet and strip lighting, chased by a masked man wearing all black. No windows, no doors, just endless corridor, and round every corner a continuation of the corridor. He's never caught me and I never stop running.
In those four, I wake normally and filled with a quiet horror that takes a day or two to go away.