Eh, my nightmares were always of those I loved being tortured, raped, or dying, while I was powerless to save them, or the exact opposite where I was in danger and nobody was there to rescue me.
My most hated nightmare was from the time my father died, right before, in which my room had a flowing, creepily-dripping river of blood oozing and rippling like a putrid Bubonic pustule, bloody handprints climbing up and down the walls, the floor replete with mostly-decomposed corpses and my bed, impossibly far from the opposite walls yet too close to the ceiling, had transformed into a spiked, bone-ridden, cage-like contraption. The spirits of the damned who had previously died there were warning me to leave, scratching on the windows and walls, tearing at the paint and the glass, screaming into the howling night to never return again, severed animated limbs and dessicated corpses crawling among the boxes in our basement, an enchained and tortured spirit vomiting an endless flow of coagulated blood, the sick metallic scent lingering like charred wood, clinging to my skin and dominating my thoughts. I don't remember how it ends because I lost all recollection of my childhood when my father died, a week later, his lungs ironically collapsing as he vomited blood and died smiling in my mother's arms.
And that is why I hate sleeping, and will stay awake for as long as humanly possible before succumbing to exhaustion. I know its not healthy, but I'd rather feel like a zombie that have those damn nightmares...