I've had one dream that may or may not have been SP. At the start of the dream I woke up in my bed and looked around the room I lived in at the time. Everything around me was pitch black; I couldn't make out any of the windows or junk I had in the room, all I could make out was my bed and a mirror on the wall across from the foot of my bed (Yep, I slept with a mirror constantly facing me back then, which is apparently a dumb thing to do as far as superstitious lore goes). I checked out the bed and mirror and everything seemed fine, the mirror seemed to show a vague reflection of the bed and me (But I couldn't make out any details). I continued to look around, then suddenly had the realization that the figure in the reflection wasn't me (I don't remember how or why I came to this conclusion), then the bed gave out from beneath me and I began falling into a dark abyss.

I woke up in the same position I had ended the dream falling in, though I couldn't really tell the dream was over. I still felt like I was falling and was unable to move or open my eyes. It lasted about half a minute and then the falling feeling faded and I was able to move again (heavily disoriented). I'd rank that dream in my top 3 worst nightmares, simply because of the overwhelming panic I felt when I realized I was awake and still felt like I was falling.