Abusive Dursleys

Harry Potter story in which the abuse of the Dursley family is worse than in canon.

Yet Another Snape Meets the Dursleys Story (Harry Potter) by Rabbit and V-Jinx-V
When Snape is called to the Dursleys' by an urgent message, he does not find what he expects to find.
Fourteen Fathoms (Harry Potter) by Vain
Snape discovers something disturbing about Harry and acts... like Snape.
The Last Will and Testament of Lily Evans Potter (Harry Potter) by Chrmisha
Petunia Dursley is cleaning the attic and finds a previously unknown copy of Lily's will. Ecstatic at her discovery, she promptly abandons her burdensome nephew, along with Lily's will, on the doorstep of her childhood neighbour (aka, Severus Snape).
Nobody Cared (Harry Potter) by Etherian
11 yr old Harry misses the Hogwarts Express. Snape is sent to find out why. What he finds changes any preconceived notions he might have had about the Boy-Who-Lived. AU, manipulative!Dumbledore, DE's, Voldy, but no horcruxes.
Pot Luck (Harry Potter) by Sita Z
Raised to despise magic, eleven-year-old Harry Potter isn't sure being a wizard is a good thing... although a certain snarky Potions Master might just change his mind.

Best Revenge

(1) The Best Revenge (Harry Potter) by Arsinoe de Blassenville
AU. Yes, the old Snape retrieves Harry from the Dursleys formula. I just had to write one. Everything changes, because the best revenge is living well. T for Mentor Snape's occasional naughty language. Supportive Minerva.

(1) The First Prophecy (Harry Potter) by Loxodonta Magica
Snape finds out about another prophecy as he sets out to learn more about Muggles. Harry becomes more to him than just a Hogwarts student.

(1) Harry's First Detention (Harry Potter) by Kbinnz
(2) Harry's New Home (Harry Potter) by Kbinnz
One lonely little boy. One snarky, grumpy git. When the safety of one was entrusted to the other, everyone knew this was not going to turn out well... Or was it? Sequel to "Harry's First Detention". AU.

(1) Whelp (Harry Potter) by Jharad17
AU. Harry is 7 years old and treated literally like a dog by the Dursleys. Will he be rescued by the wizarding world? Will he ever be fit to take on the mantle of The Boy Who Lived? childfic, preHogwarts, Sevitus. warning:extreme child abuse, violence

(1) Becoming (Harry Potter) by Unexpected Inspiration
When Sirius Black escapes Azkaban and 8-year-old Harry Potter disappears, the world is thrown into upheaval. What will Britain and Harry be without each other, and who will face the Dark? You only THINK you've read this before. I guarantee you haven't.