Switching consciousness with a creature from my dream and realizing I won't exist when the dream is over (because I thought I was the weid red rectangle creature). Creepiest one by far, and I was in front of my neighbor's house in the dream.

Bumping into miniature Jupiter in an infinite space train, then getting haunted by black and white demon faces - which caused me to wake up very scared.

Partially lucid dream where I flew on a carpet to Japan and then language-learning books started falling from the sky, and I ran to grab as many as I could. Also, it wasn't actually Japan, it was just weird grid-like suburbs with no houses, just concrete and small patches of grass. I don't remember what happened after grabbing a bunch of books.