I've taken Chantix (which makes you have crazy fucking dreams as a side effect) a few different times, so I've got a few. One of my favorites that isn't a horrific nightmare and was actually kind of profound:

I didn't exist as a physical being, I was just this presence and i could see the stars and the earth. Suddenly the earth started to sink into itself, like a blackhole was at its core.

I could hear the screams of every living thing: people, animals, plants. I could feel their fear and i knew they were praying to me. And suddenly i felt i had the energy and ability to do something.

I didn't know exactly how, but i just sort od willed the world to return to normal, and slowly it did. The cries turned to joy and praise and i felt amazing.

Then i woke up.