Re: Good Meta Stories Like Simulacrum

Metafiction is one of my biggest expertises. However, none of my metafiction material is on Royal Road (yet) so I'll link it here:

Rainbow Destructor - A sci-fi novella about a space crew trapped in a rainbow star that... well, you'll see. 
The Perfectly Regular at Magic High School - A "parody" of some anime I've never watched; it's basically an original story making fun of Magic High School Power Fantasy light novels.
The Madoka Series - Fan fictions of Puella Magi Madoka Magica about magical girls in Mexico that become increasingly absurd and self-aware over time.

And plenty more, but all I can say is that I love meta stories.