A thousand years after the fall of Equestria and the deaths of the four princesses, what killed them and shattered the kingdom has returned. A strange creature is out to wipe ponykind off the face of the Earth. The only hope is a band of ponies driven from their homes and onto a quest to find the magical force used to forge the Elements of Harmony, but is even it powerful enough to defeat this enemy.

Disclaimer: Contains G1 MLP Characters.

After coming into contact with a strange blue crystal that has the ability to enhance Unicorn Magic, Sweetie Belle accidently opens up a portal to another planet, bringing fourth an adventure with the Heroes and Villains of two different worlds.

(It could happen.... Only on The Hub!)

After being captured, Starscream is given a final chance at being allowed in the Decepticons. That is, if he can survive a trip with a new prototype machine created by Soundwave called the Trans-Dimensional Warp cannon. Which transports him to Equestria, now all he has to do is return home. With the help of some new (and old) 'friends', what could possibly go wrong? It's only Starscream.
(Potential Spoilers. This is set before Breakdown is killed and before Starscream has the Apex Armor or loses his T-cog).

On secret assignment from Princess Celestia herself, Twilight investigates a powerful magical artifact for clues to the mystery of Luna's transformation in the evil Nightmare Moon. Incautious use of the artifact sends Twilight hurtling back in time. Can Twilight discover what caused Luna's transformation? And will she ever make it home again?

Kickass cover art used with permission from Bitz.
http://allthebitz.tumblr.com/

A thousand years before Twilight Sparkle's birth, King Sombra has conquered the Crystal Empire and enslaved its citizens. From there he turns to the land of Unicornia, only for a single unicorn princess to escape his clutches and flee for help to a tiny village called Ponyville.

In Ponyville, Minty the earth pony is living in shame after her accident at the Winter Wishes Festival a few months ago. The plight of the runaway unicorn princess gives her a chance to redeem herself, but can Minty, a pony so clumsy that she seems to destroy everything she touches, save all ponykind from Sombra's menace? Only two things are certain: Ponyville's way of life will be changed forever, and she'll never make this work without a little help.

After all... what are friends for?

Those familiar with the source material -- which is hardly a prerequisite -- will notice that some events have been moved around in time, replaced, or otherwise modified. In particular, the name 'Christmas' has been excised in favor of the winter holiday from Twinkle Wish Adventure, since ponies celebrating Christmas has never once been a thing that made sense. This story is about the characters more than about the exact events (and order of events) as depicted in the animated specials.

As for the citizens of Ponyville, only the ones who showed up in the 2003-2007 (pre-"Core 7") animated specials are counted here. Toola Roola or Princess Peppermint, to pick two random examples from later releases or the massive toyline, do not count. Gem Blossom and Valenshy are also excluded from Ponyville despite their animated appearances, on account of being "jewel ponies."

SF (canon species only; no humans) Ponies were magically and genetically engineered to be the perfect servitor race. They are powerful, adaptable, intelligent and completely under the control of their creators. A laboratory accident frees one such pony from her mental chains, but how can one mare save herself and the rest of her kind if she doesn't even know she's a slave?
This is not the Equestria you know and these are not your little ponies... not yet, anyway.

Tags: Adventure, Diamond Dogs, Gryphons, NO HUMANS (did I mention that already?)
Other tags: historical, mind control, Clarke's 3rd Law, excessive use of high energy physics, before they were famous.
Detailed review by PaulAsaran.
Cover art by endrome , used with permission.
Russian translation (partial -- 'unofficially' completed in the comments)
A Soot-Covered World, book 1.

As the personal protegee of Princess Twilight Sparkle, Luna's life is more than crazy enough for a unicorn of her age. Balancing her studies and putting up with her hard-partying pegasus sister is enough to keep Luna up most nights with little or no social life to speak of. But as the only one who believes the legends that Tirek the Terrible is returning and the only one who actually cares enough to stop him, it doesn't look like Luna is going to be getting any sleep anytime soon.

Which is just as well, because she keeps having the strangest dreams about a life she half-remembers; a life of long nights spent as Princess of the Moon and a terrible catastrophe that befell her kingdom. But those are just dreams...right?

With the fate of Equestria resting on her shoulders, Luna must unite a group of unlikely allies to stop Tirek, save the world, and solve the riddle of her nightmares before they come to life.

Starswirl the Bearded, one of the greatest unicorn wizards and creator of the amniomorphic spell, has had a rather controversial life. He fought the power and even tried to clear the differences between the three races of ponies. However, this unicorn was never one to share his personal motivations or reasons: He worked for the greater good.Yet, what happens when we look deeper into his story? This is where you will find out how a colt with exceeding magical talent attempts to excel in a world where only unicorn mares are entitled to the rights of magic and sorcery. You will discover the reasons for this pony's several acomplishments and how the pony became a legend.

Princess Cadence tries to legally change her name to "Princess Cadance." Footnotes ensue. Part of the "Cadance of Cloudsdale" cycle, and a crossover with Ghost of Heraclitus's Civil Service stories. Familiarity with neither is required.

Filly Cadence turns her first heart. Part of the "Cadance of Cloudsdale" cycle; familiarity with the previous work is not required. Thanks to G.M. Berrow for the inspiration.