I have to go with Boy Who Lived by the Santi. I have yet to find a fanfic anywhere near as good as the one Santi wrote. It's good enough to be a published novel. Sad that it got abandoned.

 

The Shadow of Angmar. You can tell just how much effort was put into each chapter

 

My Immortal, obviously. How is this even a question?

 

For my second choice Id go with the Vincet series by nos tres reges. Just a shame the author Rob abandoned it after book 2. If he had finished the series I doubt any other fanfic would come near.

 

I don't want to count anything abandoned or WIP. I liked Sum of their Parts, Hermione Granger Demonologist, and a few other shorter ones. All the novel length ones needed a ton of editing, but Basilisk Born comes to mind as having lots of promise. A few others do too. My favorite of all fanfics is The Last Ringbearer, but it is a LOTR fic, not HP.

 

I'd like to go with Intoxication as well. It's so fucked up but ridiculously well written. Best Harry Daphne ever.

Lie I've lived deserves a mention as well.

 

Is there a working link for this? The one in the review thread https://forums.darklordpotter.net/threads/intoxication-by-nos-tres-reges-t.15341/ errors out.

 

Download the dlp archive

 

Without Doubt, What Would Slytherin Harry Do? by Big D on Diet..... hand down nothing can ever come close to this one ever!

 

The Downward Spiral Saga

 

What a useless necro when the question was definitively answered in post #4

 

I've not re-read them since the originals, but I'll go by what I remember most fondly.

I think the fanfic with the biggest emotional stranglehold on me might be Circular Reasoning by @Swimdraconian -- who I should really show more love. I see you there updating your fic on FF.net buddy!

Or maybe Ectomancer for another angle. What a fun, crazy world.

I should dive back in and reread them soon to see how well it holds up, or conversely see if my tastes have been atrophied by reading one too many MTLs. D:

 

The Unforgiving Minute by Voice of the Nephilim and Legend by Polyphoenix are unmatched in giving me the shivers. I have a lot of good fics I like to read, but these communicate on a different wavelength.