DCU
Mobius Paths, by Marcelo. Gen. (ca. 300 words)
This is short, but with a very neat though somewhat creepy premise: What if Alfred Pennyworth was really J'onn?
Stargate: Atlantis
None Can Quite Extinguish, by Cate. Slash, John Sheppard/Rodney McKay. (ca. 45,300 words)
This is a look at how things might have gone if there had been more survivors of Sateda, who then stayed on the planet. It has great world-building, and the internal politics of Sateda and the Genii in this story are interesting.
Curiouser and Curiouser, by Gaia. Gen. (ca. 4,300 words)
I wished this AU had been longer to really explore this world, but even as a short story the premise is great. In a reversal of the show's setup the Pegasus galaxy sends an interplanetary expedition led by Teyla Emmagan to search for the lost world of Earth, where the Ancestors are said to have gone, only to find Earth overrun by the Ori. The expedition, with Genii and Satedan forces find remnants of the SGC and set out to help their resistance against the Ori. I would have liked getting an epic chronicling their adventures, and seeing the conflict of the Pegasus expedition's goal to find weapons against the Wraith and Asurans, with the Milky Way priority of fighting the Ori, but this time with the Pegasus cultures at an advantage, and this story is too short to mor than tease with that, but very intriguing with its shift nevertheless.
Cage for Gods, by Kat Reitz and Perryvic. Slash, John Sheppard/Rodney McKay, Carson Beckett/Rodney McKay. (ca. 63,950 words)
In this AU Rodney has ascended in Tao of Rodney. I liked the story for its interesting view of the Ancients and ascension.
Raiders of the Seven Systems, by Martha Wilson. Gen. (ca. 9,150 words so far) WIP
It's a space pirate AU, with what seems so far like a very cool premise for the Pegasus cultures, and lots of action and suspense. I'm definitely hooked.
Good Guys Don't Always Wear White, by Nel. Slash, John Sheppard/Rodney McKay. (ca. 31,000 words)
This is a fusion with the first X-Men movie. I liked how the mutant powers were distributed among the SGA characters and their histories adapted (casting Michael as Magneto was especially awesome), and it was a good action adventure, that changed enough from the movie to keep the plot interesting too.