Man, picking just a few is tough. There's this one that's stuck with me for ages—'Chrysalis' on AO3. It's a Blake/Sun fic, but it's not the usual fluff. It's set after Beacon falls, and it's all about Blake dealing with her trauma and Sun trying to help without pushing. The writer gets Faunus politics so well, weaving it into their quiet moments in Menagerie. It feels less like a romance and more like two people figuring out how to heal, and the slow burn is agonizing in the best way.
I remember staying up way too late reading it, and the part where Blake finally tells Sun about what the White Fang was really like for her? That hit hard. It's not a happy story, but it's so satisfying to see them build something real from the wreckage. You really get the sense they're partners in every sense, not just a ship.