Recommendations
I'm going to use this to recommend gen, het, and adult fics, since I know how hard it is to find good fics. Heh. Asterisks (*) denote my favorites. Adult fics are not just smut and PWP; fics that are heavy in violence, language, or other mature themes will be placed under Adult. This list is by no means complete!

Gen
None yet

Het
Phantom of Hogwarts by Good_Witch
How in the world does Hogwarts to come to be doing a performance of The Phantom of the Opera? And just why is Snape so pissed about it?

Adult
Dark Gods in the Blood* by Hayseed
A wandering student comes home, a broken man pays his penance, and a gruesome murder is both more and less than it seems. Some paths to self-discovery have more twists and turns than others.

Getting the Hang of Thursdays* by Hayseed
A good day goes bad and then gets far worse than Severus could ever have imagined. Again and again and again.

The Long Black Coat by bloodcult_of_freud
Inspired by the song The Man in The Long Black Coat. A future where Voldemort has triumphed narrated by Hermione's mother. Not a cheerful story.

Rosemary for Remembrance by Hayseed
A battle won is often also a battle lost. In these cases, faith is hard to come by.