After a dragon attacks Ponyville, Twilight discovers she has a strange new ability. What does it have to do with the dragons that are cropping up everywhere, and what will it mean for Equestria? (Skyrim Crossover)

After an incident with the heart of Liberty, Niko Bellic finds himself awake in an unusual hospital. He quickly learns that he is no longer in Liberty City. His rough, gravely world is about to be turned upside down.

Luna has had enough of Celestia's games, and has found the perfect means of revenge. Using a long-forbidden spell, she transforms her sister into little more than a small filly, all so she could pull the greatest prank ever. Unfortunately, she soon learns that before you fool around with dangerous magic, you really need to read the fine print...

A sequel can be found here.

Applejack finds a strange visitor in her apple orchard one day, with even stranger stories to tell...
MLP/L4D2 crossover. My first story on FiMfiction.net! May add more tags as story progresses.
Credit for the image goes to brokencreation on DeviantArt.

With the events of the Molestia Night behind them, Luna's mind wanders around the topic. It is only a couple days later that she remembers some very crucial details about her stay on the moon. With the night young once more and her passion heavy, she seeks answers to the questions that her older sister brought up, as well as to her own. The way she does it, however, turns out to be very... Naaaaughtyyyyy...

-The events that take place in this story kick off directly after the events in the Epilogue of Princess Molestia.

An object of unknown origins crash lands in the no-pony's land between Equestria and Gryphon territory. Princess Luna and Twilight Sparkle race to beat the Gryphons to the crash site, but discover more to the crash than they originally thought.

The star system Omega Centauri was just another oddity on a map to scientists in the not too distant future. However when they found the star was orbiting an earth-sized, earth-like planet instead of a black hole as its motion had suggested, a mission was scrambled to investigate this most unusual of celestial behaviors.

Hamstrung by politics, and nearly crippled before it began, the 'Lone Ranger' mission was reduced to just one crew member and left to his own devices.

These are the logs of Arrow 18 and its lone commander. This information is classified TOP SECRET by the Global Space Agency.

Do NOT tell the princess.

In an alternate reality, Discord found his love of chaos came in handy for babysitting young foals. For two thousand years, since he and the princess' were kids, he's babysat nearly everyone in Equestria. Now he's babysitting the cutie mark crusaders, and while he does he recounts with them his many babysitting jobs of your favorite characters as fillies, one by one.

Coach and Louis from Left 4 Dead get trapped in Equestria. And the ponies seem to be taking it quite well to have two battered, covered in blood humans...Or do they? Meanwhile, back on Earth, the survivors have to find out what happened, and try to rescue their lost friends! But will they be able to get back? And, can the ponies stop the infection coming from the two, infected blood covered humans? (Warning: This story has cursing)

Sequel to Envy and Arrogance.

Sweeping changes are taking Equestria by the reins as the conflict between Harmony and Discord becomes more fully understood, and, at the same time, less clear than ever before. With nopony to count on but themselves, and sometimes not even that, the Elements of Harmony are forced to either punish the guilty or leave all they know at the mercy of Lady Luck as they go up against two of the most powerful entities in all the world.

(Cover image by HereticOfDune; illustrations by LingLiJing and Denial.)