My most famous story, by far, is Snit. Some of you are familiar with the genesis of that story, but I think a lot of you are not, at this point. So I'll tell you about it.
A long, long time ago, I was drunk, and I was also on FimFiction. Specifically, I was in the comment section of one of Device Heretic's blogs, which sadly no longer exists. The discussion had turned, somehow, into the intersection of Star Trek episodes and Ponies. I made a comment about putting Celestia and Luna into the place of the two Picard brothers in the TNG episode "Family". And then I said something terribly fateful.
Luna and Celestia coming to blows, rolling down the Canterlot mountainside and ending up laughing in a heap in front of Twilight's tree, which they invade in order to drink her stash of cider. Twilight is confused and strangely aroused.
They egged me on. I had more whiskey, and I started to write. The first part of the fic to be written, and then posted in Device Heretic's comments, started in the middle of the first chapter, where Twilight wakes up the first time.
I was goaded and egged on further, and generally encouraged to fill it out and post it as a story. And that's how Chapter 1 was made.
To write the intro, the very first part of the first chapter, I actually took a transcript of the scene in "Family" where Jean-Luc fights with his brother. Then I re-wrote it with the princesses cast in that role. Then I re-wrote it again into what's now posted for the story. I recently came across the fragment that's more directly derivative of "Family", and I thought I'd post it here, to show an intermediate step between the story's origins, and its current incarnation.
So, without further ado, "The Princesses Re-enact 'Family' from Star Trek: The Next Generation":
Luna snagged the bottle in the glow of her magic and pulled it over to her nose. The whiff of strong spirits sent her eyebrows crawling up toward her mane.
“We do not believe we have seen you drinking anything so strong before. Nothing--” there was a suggestion of archness “--that would leave you out of control.”
Celestia's mouth was small and her lips thin; she stared fixedly out the window and at the sun.
“I suppose so.”
“This, “ Luna gestured with the bottle, “most assuredly will.”
The moon princess did not wait for a reply before beginning to pour herself a glass of the amber liquid. She fixed her eyes carefully on the flowing brandy—and definitely not on her sister—as she continued, “Now there is something we would like to see.”
This at least drew a flicker of interest from Celestia, “What's that, sister?”
“The perfect princess out of control.”
Luna waited a moment, to see if her sister would rise to the bait. Apparently she would have to do better.
“Would you object if we asked you a question?” Celestia made a non-committal noise and gesture, and Luna took that as her cue to continue. “What, by Discord, happened to you in there?”
Luna watched her sister closely. She could actually see the growl being suppressed, packaged up, and carefully set aside. When Celestia did speak, there was barely a waver to her perfect maternal warmth.
“You know what happened.”
“Not precisely. We gather that you were beaten. Hurt, imprisoned, “ Luna paused, steeled herself, and plunged in the verbal knife, “humiliated in front of your faithful student.”
Celestia did not so much as twitch a muscle, and the silence goaded Luna on to twist, “We always believed that you needed some humiliation. Or humility. Either would do—Celly! Why are you walking away?! That is not your style!”
The white alicorn said nothing, and Luna was forced to take long strides catch up and keep up with her.
“I am tired of fighting with you, Luna.”
“Yes!” she spat back.
“Yes... tired of Equestria too, then?” Luna looked to the sky as she followed her sister into one of the palace gardens, wearing a maliciously wistful expression, “The great princess Celestia of Equestria is thrown to the palace floor, and now she is ready to plunge straight into the bottle. That is not the sister we remember. Still, we suppose it must seem like an ideal time to give up, hm? Your sister returns after a thousand years, there is a fine little unicorn around who idolizes you too much to resent what you do to her; it is an opportune time to retire with a hero's farewell.”
Celestia's nostrils flared, but her voice was still stable, “I am no hero, and nobody's idol.”
Luna scoffed, “Of course you are. Admit it. You could never settle for anything less than that and you never will.”
“That's not true! I never sought--”
“Never sought! Never sought the Platinum Crown? Chancellorship? To be the martial hero with your wings splayed in victory?”
“Chancellorship! Wings splayed in victory?!” Celestia's voice caught in her throat, “Are you still so jealous?”
“Yes, damn it!” hissed Luna. Her cool was slipping, and she cursed herself for her inability to control herself as well as her sister, then again for still—still!—drawing that comparison automatically. “I was always so jealous, and I had a right to be!” Luna bulldozed right through the first sounds of Celestia's protest, “I was always 'Celestia's sister', watching you receive every honor and cheer, watching you flout and ignore every rule you set me and your ponies set you, and watching you receive greater accolades for it each time!”
Celestia finally raised her voice to interrupt Luna's tirade, “Why didn't you break a few rules, then?”
“Because I was the younger sister! I was trying to be good enough! For you, for your ponies, so that they would love me as they did you! I followed your strictures faithfully, and for my devotion I received your and everypony else's scorn!”