Anguissette by jezzieChapter 10. Ron uses extendable ears, makes wrong assumption and plans to get Snape sacked.
Choice by juanafever33 chapters. Everything turned upside down. Nobody believes Hermione, Minerva is hateful, Albus heartless, Lavender and Parvati her only friends. Seriously grammar-challenged autor manages, after 20 chapters or so, to create a real and interesting relationship between our heroes and a number of Slytherin girls. Can't wait to read what comes next.
Sweet Mercy by vanityfair12th chapter. The third go with Voldemort. Hermione and Snape are the only ones who care, but neither is in any position of power or trust. Ministry worse than in canon.