More updates here and added to the
masterpost. Behind the cut: 5 Harry/Nick, 2 Liam/Louis, 2 Harry/Niall, 1 multiship.
Harry/Nick
Werewolves of London, by gorgeousnerd, 23k. Harry's family are all werewolves, but Harry's not, quite; Nick's family aren't, but he is. Lots of interesting things on finding your place in the world, both with respect to werewolves and not--among other things, Harry's genderqueer. A lovely slow burn romance, too, and some interesting mythology.
you are the sweetest, sweetest song (i could hear your song forever), by jeyhawk, 85k. Alpha Nick and omega Harry are friends. This is the story of how they get together (and then have lots of sex). Very, very sweet--there's very little question they're getting together, just a question of what their relationship will look like when they do. There are some nice details of the way the A/B/O biology functions in this world, too; I like stories that explore that. Just a comforting, sweet story of Nick and Harry in love. :)
Make It Fashion, by junkshopdisco, 14k. Nick was obsessed with Harry when he was on Top Model; then he sees Harry in a show and they become friends. And other things. Slightly ridiculous in the absolute best way and very funny, plus some things that are hot in ways I'm not used to things being hot in this fandom.
An Abridged Sexual History of Nick Grimshaw: A Love Story, by mrsronweasley, 13k. What it says in the title: a history of Nick figuring out sex with boys, and then sex with Harry. It's all great, but I think my favorite bit word-for-word is the last short chapter. If you're looking for a Nick Grimshaw character study with lots of sexy parts and also Harry Styles, this is definitely for you!
untitled, by ymorton, 2k. A lot of this author's stuff is angsty (and I love it), but this is just the right amount of sappy-sweet, an entire romantic plotline packed into five minutes of fic timespan. I love that, too.
Liam/Louis
Not All My Jokes Are Funny, by ferritin4, 5k. Louis pranking various people in the band, with various reactions. A fun bit of Louis/Liam romance with plenty of misunderstandings.
Miss Missing You, by harriet_vane, 16k. Louis wakes up from a coma having forgotten most of the last year. This is a normal person AU, so it mostly focuses on what this does to his relationships, rather than combining that with what it does for his work life/fame. It has a different than usual (for fic) take on what makes relationships difficult and how those difficulties can be worked, which I thought worked well; definitely some angst throughout, though it's not too heavy on it when it does come up.
Harry/Niall
move your world a little closer, by countthestars, 46k. Niall lives in Pahrump, Nevada, and hosts a late-night conspiracy theory talk show; Harry's one of his regular callers; Louis and Liam are his best friends. This takes a common fanon characterization of Harry to its logical conclusion, and does it brilliantly. The Niall/Harry stuff is sweet, and the Louis/Liam stuff is--well, also sweet, but very appropriate for them. There's also a lot in here about hope and the future and what it's like to make plans when you're young and unsure about things, which I found very relatable. (Also: minor tentacles.)
Baby, I, by makesomelove, 23k. This is the kind of fic that would have gotten called crackfic in Harry Potter, but which nonetheless is emotionally very serious (though not solemn). It's all about making connections and accepting reliance on other people and love and stuff. Just with a weird version of lactation kink on top of it all. A great Niall in this, with realistic emotional reticence, and a pretty weird Harry that actually is probably as weird as the real Harry, unlike a lot of fic. I wouldn't start out your 1D fic reading with this fic, but once you're comfortable with the characters it's amazing.
Multiple ships
All the lifts home and all the mixed feelings, by becka, 27k. A high school AU with a bunch of intertwined stories--all connected to at least one other story, but not always intersecting with all of them. In one story, Niall and Louis are high school boyfriends trying to navigate Niall's last year before uni and Louis's first year out of school; in another, Harry is interested in Nick, but Harry's a student still and Nick's a teacher (at a different school). The Nick/Harry stuff was handled especially nicely, I thought, with unusual care taken with the difficulties of a relationship with a power dynamic like that. And Louis and Niall are just so sweet together, even though they have some situations of their own to work through. Lots of good stuff, and it never stays too long with any one story--this is a lean, aerodynamic machine of a story, giving you exactly as much as it needs to give you an emotional punch but not a moment more.