First time I ever had sleep paralysis was definitely the scariest. I didn't know what it was at the time, so I swore I was getting possessed by a demon.
I had my eyes open and was looking out across my room at my blinds, when I tried to move and found that I couldn't. The more I tried, the harder it became, and my limbs started to feel like they were burning. It felt like my bone marrow was on fire.
Then I started to hear this demonic laughter, and I felt, like I could have sworn, that there was this dark presence creeping up behind me. Then the laughter of children started to chime in with the demonic laughter, but eventually it ended and I could move again. Truly terrible.
Another time, I was laying in bed with my hand hanging off the side, and I was about to fall asleep. Started getting sleep paralysis and tried to fight it off, but not before I vividly saw a ghost walk up and hold my dangling hand.
Sleep paralysis is terrible, and I had to stop taking naps because I got it so often. Now I have some semblance of a circadian rhythm and I don't get it as often.