I've noticed a considerable amount ROM hacking fan art floating around the internet, but it doesn't look like there's anywhere to hoard it all!
So, I'm hoping everyone will help us build a glorious collection in this thread!
I'll begin with this amazing SMSR drawing created by
Quasmok.
I'm sure I've also seen fan art of
Kaze's
Super Mario 64: Chaos Edition on DeviantArt before.
Contributions to this thread which are of adequate quality will earn the user a
Super Appeal badge, you must also be the artist to receive this award.