According to Den Of Geek just about every kitchen-sink genre show hits these six at some point.
The Time Loop
Ascension To A Higher Plane Of Existence
The Dream Episode
I only did three of them in the course of The Watch House and the Bodyswap wasn't actually my idea. Mostly because I was sticking with the Buffyverse and there had already been high-profile Ascending, Dream and recent Time Loop episodes. I did do some less common ones, like a Descent Into The Underworld. And admittedly I hit Alternate Dimensions a few times, and that's where our Doppelganger/Double/Duplicate came from. (Which Buffy did as well.)
I naturally had a Time Loop in my Doctor Who game. Who being back as of 2005 might have stopped me doing one in TWH.