Alright, I've got a batch of recommendations to share:
First, a pair of seconding recs from previous entries in the thread:
In the Language of Flowers
Harry Potter AU where Petunia has magic instead of Lily. Genuinely one of the best things I've read to the point I've reread multiple times and several sections still manage to make me tear up.
Or the
Island of Fire series about colony building in the world of Temeraire by a bunch of stranded Triwizard tournament spectators and contestants with dragons on a desert island.
If you like good writing with world building you will like esama's stuff. Unless you can't handle slash. Then you're SOL.
I didn't realize that I hadn't seconded In The Language of Flowers yet, and I got reminded of the Island of Fire when epistolary stories were mentioned here in connection with QAB.
And now for new recommendations.
A Small Gesture Of Great Impact, by ekrolo2
A For Want Of A Nail Star Wars Revenge Of The Sith!AU that starts with honest communication, which is something I always enjoy seeing. Anakin is able to confess his relationship to Padme to Obi-Wan right before the rescue mission to recover Chancellor Palpatine, and everything changes from there. This isn't a perfect world fix fic, there are some pretty major character deaths in it, but the ending is definitely far brighter than canon.
area cryptid upset no one bothered to inform him of his tragic backstory, by crimsonseekers
A Post-Kamino, Post-Shie Hassaikai MHA fic that leans heavily into the 'chaotic gremlin' viewpoint of the League of Villains that was common before the whole Meta Liberation Arc and everything. The concept of the story is that Dabi, aka Todoroki Touya, doesn't actually know who he is, and has in fact spent years trying to piece that information together. The rest of the League of Villains gets in on helping him with that, which spirals into the events of the story. One of the tags is 'Crack Treated Seriously', which fits it extremely well. It is a hilarious story, along with the various follow fics, and I return to it often for a laugh.
Four Things that Wren't Adequately Covered in Mulan's R.A. Training, by NaomiK
A fairly quick one-shot that nonetheless does an excellent job of laying out a 'Disney Princess Real World AU', one that I would honestly love to see more of, and get to see more character introduced [Elsa and Anna coming in having been separated by their parents, with Elsa locked away behind their parent's high expectations for her / Moana having to deal with her dad being very unwilling to let her come to school and her grandmother having helped her apply / Raya being a rebel that causes a lot of headaches for Mulan by going off and drinking or otherwise being disruptive and contrary / Jane being one of the professors at the school who seems very uptight, but is rather wild when she is off-duty and letting her hair down, etc.]
Mama Bear, by ArcticVulpix
What is Alma Madrigal just wasn't the absolute worst? That is this story summed up. Alma puts her family first, rather than raising them to 'serve' the village, and everyone is 100% happier because of it. There is still conflict, generally just from lazy and greedy villagers, but it all still works out.
Pity of the World, by appending_fic
This is a big Pokemon AU, which mashes aspects of the games, manga, movies, and more into the anime timeline, centered on the idea of Ash ending up travelling with Jessie, James, and Meowth, rather than Misty and Brock. This isn't him joining Team Rocket, as they aren't part of the Team in this, but they are still thieves, just more benevolent ones focused on rescuing Pokemon from bad trainers. Anyway, like I said, this story is a very complex AU, diving into a lot of very interesting worldbuilding. There are some aspects that drag a bit (I dislike some of the characterization choices for Misty and Goh), but overall, the story is very interesting and the world one I've revisited a few times since the story finished.
