These recs are either R or NC17. Bah humbug to Gen.
Also, I don't warn for teacher/student relationships, or sex between an adult and a teenager age 15 or above. As most of the recs are Snarry, I assume that if you're looking here, you're okay with all that.
Snarry
So Lonely Without Me by Calligraphy "Two men, two rooms, a war. Slash, Harry Potter/Severus Snape."
----This story has some of the best dialogue ever, and one of the finest Harrys. It's easy to make the Slytherin characters compelling, but Gryffindors tend to come off as Mary Sueish. This Harry is trully messed-up- but he's still endearing and fun, and he holds his own against Snape in the dialogue.
The Challenge by Cybele "Snape finds himself the subject of seventh-year mayhem. Response to the
Severus Snape Fuh-Q Fest scenario challenge 81: Snape gets kidnapped."
---Snape has an amazing monologue about love. So, it's poignant. And there's an amazing prank war between Slytherins and Gryffindors. So, it's fun. Plus, it's Cybele. Please, read.
Laws of Magnetic Attraction by Go Seaward."Harry Potter, war hero, comes home after sustaining an injury in the service of his country-only to find that the war at home is much more dangerous. "
---I generally shy away from AU Non-magical stuff, but this piece is just poetic. Even though Snarry is my OTP, I sometimes don't understand how Harry and Snape can stand each other. Fics have to work hard to make them believable as a couple. This story addresses their personality conflict in a refreshing way. In this universe, you can see why Snape and Harry would settle for each other- though I hate to say settle, because it's so much better than that.
Everybody's Fool by ClueGirl "Bruised veteran of too many heartbreaks; cynical, jaded drunkard; Wardwright, war hero, recluse, and part time matchmaker. Next target -- Severus Snape, who has a lot to learn about love."
---Cluegirl is amazing at writing pathetic-but-stoic. Even when the characters are constantly getting kicked in the face, they still somehow maintain their dignity. While this is one of Cluegirl's "lighter" fics, it still delivers a sucker punch.
Anachronism by Starcrossed. "Upon waking up, Severus finds himself not recovering from Nagini's bite, but healing after a long-term mysterious illness. Not only must he uncover the mystery of the cause of his affliction, but also deal with his lover, who is the very last person he wanted to ever see again: Harry Potter."
---The sheer inventiveness of this fic awed me. The plots twists are quite brilliant. Snape, at first, pissed me off. Let's just say that he's Snapeish to the max. It's forgivable when one considers what's happening to him. Please, don't let the warnings deter you. As far as Non-Con goes, this is one of the easiest depictions of it that I've read.
The Familiar by Resonant "A potion goes awry."
--Probably my favorite short Snarry. Harry turns into a frog, Snape adopts him. One of the fluffiest Snarrys out there, and also one of the smartest.
Help Wanted: God and Executioner by Pir8fancier "The last year of the war, and Harry’s getting a first-class primer on death, loss, the sanctity of one’s conscience, and sacrifice."
-- It's the best example of "Snape shows Harry how to cope with the horrors of war." This is my favorite Snape: he is mean yet congenial, remote but very human.
A Spell to Turn Tigers into Butter by Amanuensis "Comparing the stories his enemies tell, we see that Harry remains resourceful even in the worst circumstances..."
--I hate to rec this, because it aint romance and well... Harry's life just sucks. But this story is so intelligent, with such an amazing twist at the end, that I'm sort of in awe of the writer. It's one of those rare dark fics where the psychology overpowers the horror, so by the time you're halfway through it, you've nearly forgotten you're reading a non-con sex slave story. Plus, it's just plain funny at points. Also features Lucius/Harry
Tea Series Telanu
--There's no summary for the whole work. Probably because every Snarry devotee already knows this story by heart. It's my favorite Snarry, and probably (pathetically) in my top 50 works of literature. You'll be transported into the world of Snarry Hogwarts so completely that you'll walk around in a fog for days after reading.
Harry + some other guy
Harry Potter and the Mai Tai of Doom by Sushi (HP/LV)
---Couldn't find the summary. Basically, Harry vacations in Hawaii, hoping to get away from the war. Who does he run into by the tiki bar? That's right. Hilarity ensues. Seriously, this story had me howling in laughter. Voldie and Harry throw water-filled condoms off their balcony. Crack at its best.
Maelstrom by Hollycomb (HP/TL)
"During a family vacation, tensions between Harry and Teddy come to a head."
---This story has the best character study of adult Harry I've ever seen- and Teddy is fantastically drawn. They both do and say things that make you want to kick them in the head, but they are so endearingly human, you're rooting from them wholeheartedly all the way. Hollycomb seems to really understand human nature, because the relationships in this fic are complex and fantastic. Warning for infidelity- but if you can handle a little angst, this fic is totally worth it.
The Malfoy Guide to Productive Extortion by Mirabella (HP/DM, HP/DM/RW)
"Harry's either drunk and horny or drunk and cuddly, depending on your point of view. Ron's straight but no one holds it against him. Draco could hand out detentions, but he has a better idea"
--Hilarious. I don't read a lot of Draco Malfoy. But I include this because Mira's Draco is amazing and charming as he makes fun of the drunken Ron and Harry. And Harry is adorable. It's not hard to make hapless Harry adorable, but this Harry is unique, I promise.