Rec the Thing

(All fic) These are my favorites--at least, the ones on AO3.

Syllepsis, by Paian (Stagate SG-1)
Daniel is working alone at Jack's house when Jack's ex-wife turns up. Sara recognizes the truth about Jack and Daniel's relationship immediately. Her conversations with Daniel and then Jack are beautiful and moving and cathartic. The Jack/Daniel sex that follows is gorgeously written. 
Lovely and Tatters, by Martha  (The Sentinel, Stargate SG-1, Angel:The Series, Cthulhu mythos)
I don't like horror. At all. But horror by Martha is an exception, and exceptional. This series actually starts with Unsleeping, set in The Sentinel, which introduces the Lovecraftian element. But I love the SG-1, Sentinel, and Angel teams and the way they interact. Marha shows us a Daniel Jackson hurt and on the run, lets Jim and Blair come to his rescue, calls in SG-1, and then brings Angel and his team in to confront the apocalypse. The relationship between Jack and Daniel is tender and sexy, as is the relationship between Jim and Blair. The Angel team is as weird and funny and heroic as always. But the best thing about this series is the way it shows us how these very different people look to each other.

freedom's just another word for nothing left to lose, by synecdochic (Stargate Atlantis)
Post-series. John is dead. Rodney has to build a life in academia without him. He struggles, not just for a bearable life but for a meaningful way to share the lessons he has learned with his proteges. Stunningly smart, beautiful story.

September Song, by Kat Allison (Highlander)
The world is slowly sliding toward the end times. Methos visits Duncan's barge in Paris to talk and to make love in the face of apocalypse. Given our times, this cuts to the bone. Read it anyway. It's a genuine classic.

The Unvictorious Ones, by quercus (Stargate SG-1)
The Tollans ask Daniel Jackson to help assess the conditions on a planet where ethnic cleansing is reminiscent of the Cambodian horrors. Jack and Paul Davis accompany Daniel. There's a dreamy quality to this story that helps to alleviate the terrors of what the men witness. This is an idealized Daniel whom Jack deeply loves, which may be why Jack is the one who is most traumatized by their experience.

grounded, by Pares/kormantic (Stargate SG-1)
By now you need some humor. This is my favorite. It's Jack/Daniel, and it's sexy, smart, and funny. I love it.