Well... this is an interesting topic.
I've had a whole bunch of experiences beyond poltergeist to be quite honest. However, I am going to share two of my experiences.
Experience#1
During those times unfortunately, I was incarcerated. Yes, it was the most difficult time in my life. Anyway, I was alone in segregation for a while and had few experiences there, but one night. In a dark cell, an appearance of my own beloved sister appeared in front of me, and at that time I thought I was communicating with her somehow. All of a sudden, she shapeshifted into a clear liquid bacterial teddy bear, and then whatever that was, was gone. That same night after my sister left, the cell door opened up, and I thought that there was a correctional officer coming to check up on me. Nonetheless, there was like a misty foggy smoke that was coming from nowhere outside the cell, and then this tall man with a black trench coat and suit came into my cell, and he sat right next to me. This man had blonde hair with a pony tail and looked like a white man. He said "I am a Freemason." And, I don't remember what else he said but I remember him saying that The Illuminati are the bad guys. Now, the cell door was open and there was no sound from the outside lobby. Few seconds later, the tall man got up, and left living no trace of him, like he vanished. And, I never saw him again. Now, this was before I knew about The Universe and His/Her appearances.
Experience#2
They finally took me out of segregation, and I ended up in another cell with a cellmate. One night, I happened to look outside the window and I see a Landscape, and it look like it was taking form. There was a stream of a river flowing around with a small tiny waterfall . Also, there were spotlights hitting the ground of that landscape, and I could hear techno or dance music coming from nowhere outside. Note, I was in prison, and there was no way that music would play here. Anyway, the landscape look like It was a mountain top, and the ground looked so clean that looked like sand from a dessert. And, there you have it folks, 2 of my wonderful experiences. I hope you enjoy this. Grundy, I know you will.