asked for Haven recs. There might be more comprehensive recs lists later in December but I'm going to start here with recent fics on AO3 that I've particularly enjoyed.
Aches by Jadzibelle (!unfinished)http://archiveofourown.org/works/2559392
Current WIP that claims most of my fic-reading interest. It has 18 chapters and is 50k long already. A canon-divergent look at Duke and Nathan's return to Haven with Jennifer in season 4. Lots of warmth and friendship and occasional fights with indications of building up to something more.
Of Sea Monsters and Safety by embolalia http://archiveofourown.org/works/2613521
A Duke and Nathan as children fic with a bit more depth than the usual cuteness and scrapping.
Five Times People Were Utterly Oblivious to Their Relationship and One Time It Was Too Obvious to Ignore by lovesrogue36, Rabbitt http://archiveofourown.org/works/2613593
Awesome 5 Things style fic with misunderstandings of the Audrey/Duke/Nathan relationship from various Haven townsfolk, with a bit of action and a bit of humour and a bit of sexytimes thrown in.
I'm Your Boogeyman by Miah_Arthur http://archiveofourown.org/works/2501681
I can't recommend this one enough. I'm biased, because I beta-read it, but I love it to bits. This is Miah's Halloween fic for spook_me, when we were both knocking ourselves out to try and finish spook_me at the same time. Haven people are disappearing in their sleep after getting a specific nightmare; Nathan has the nightmare and determines to fix the Trouble when he's taken. But Duke's next in line and when Nathan comes a cropper trying to save him, everything's down to Duke.
this night that is past by whiplash http://archiveofourown.org/works/2532530
Cute mid-season 5 Naudrey plus Duke friendship where Nathan is sick.
begging at happiness' door by whiplash (!unfinished)http://archiveofourown.org/works/2392160
This is the first chapter of a WIP that hasn't been updated in some time, but even chapter 1 hits such an awesome concept and potential that I can't not mention it here.
Lavender by audreythree http://archiveofourown.org/works/2369189
Duke/Jennifer drabble, season 5. I cannot say anything about it without spoiling it, other than ow
Issues of Consent and Old Lovers by lovesrogue36 http://archiveofourown.org/works/2357786
Duke/Mara/Nathan porn. Yeah. Just that. *whistles innocently*
Theseus and the Minotaur by Miah_Arthur http://archiveofourown.org/works/2260302
Haven acts out Greek Mythology, Duke is caught up in the plot, Dwight is somewhat baffledly trying to make sure he doesn't get harmed in the process while getting distracted by the sight of Duke in a robe. Duke/Dwight.