Stargate: Equestria

They've met gods, fought gods, blown up suns, found Atlantis and a host of other things. Now, SG-1 must face their toughest challenge yet - Equestria.

Stargate: Equestria is a Stargate SG-1/My Little Pony: Friendship Is Magic crossover fanfic written by Bosstone in which the SG-1 team, after Daniel makes a mistake while dialing Earth, wind up in the cute and colorful lands of Equestria. At the moment it consists of two stories.

Stargate Equestria: Connection deals with the team arriving in Equestria, meeting the main cast, Celestia and dealing with some Jaffa, while learning the long forgotten history of Equestria. Told from Jack O'Neill's perspective, who is finding it hard to wrap his head around the place he's wound up in.

Stargate Equestria: Incursion is set after the events of Connection and has remained unfinished since 2011. In it an old enemy mentioned in Connection has returned and SG-1 is leading a mission to liberate the planet.

Has its own intro as well.

Tropes used in Stargate: Equestria include:

Call Back: "Undomesticated equines could not remove me"
Cool Gate: It's a Stargate crossover, so it comes with the territory
Deadpan Snarker: Jack O'Neill, naturally.
Even Jaffa Ponies Have Standards: When Teal'c and O'Neill question the Jaffar pegasus who ponynapped the Cutie Mark Crusaders, he admits to being ready to interrogate them but is offended at the idea that they'd torture them.

"“We would not have hurt them. We will do what we must to serve our goddess, but we are not needlessly cruel.”

Genre Savvy: SG-1, of course. They also hang a few lampshades.
Interspecies Romance: Almost, anyway, between Jackson and Twilight Sparkle. O'Neill is creeped out to find out that Jackson likes Twilight in that way.

"If both participants are sapient beings, is it really besti --"
"Do not finish that sentence, Jackson."

Lampshade Hanging: Members of SG-1 hang lampshades on the fact that the locals always speak english, there's always some threat and there's always some keeper of ancient knowledge
Mildly Military: Gets subverted hard when O'Neill sends Rainbow Dash and a wingpony off to spy on the Jaffa ponies. When Dash returns, she reveals that she went by herself despite what O'Neill said, at which point he rips Dash a new one and explains why she should have taken a partner.
Shout-Out: O'Neill references Super Mario in Incursion
Remember When You Blew Up a Sun?: Carter's famous action is mentioned in Connection
Who's on First?: In Chapter 5, O'Neill wanders Ponyville and meets a certain brown colt with an hourglass cutie mark. O'Neill introduces himself and asks for the pony's name? The answer? "Who." It goes on for a brief time before Fluttershy shows up to save him.