Let’s start with a simple question: what’s your favorite fanfic? If you can’t decide, maybe break it down: favorite one-shot, favorite long-form (100k+), etc. There’s so many great stories in the fandom!
Stories by Northumbrian … start with “Tales of the Battle” and continue. His pre-Battle stories are not bad, but he really shines as a writer of post-war stories.
There are so many I like. That said, I think A Black Comedy would take the cake It’s just a stupid, fun, ridiculous fic. I’m usually not into comedy types but it’s so good.
Long form is currently between DPaSW and Prince of Slytherin.
Frickles’s stories have taken a special place in my heart, A Straight Flush, A Discordant Pattern, and I think his currently most popular fic, a Haphne one, A Malignant Ruse is also great.