"Group," by Celli Lane. Good Ghod, this fanfic's six years old now. Buffyverse, set after the episode "Ted" (guest-starring the late John Ritter, as Joyce Summers's evil robot boyfriend): Buffy, assumed to have been traumatized after the whole Ted thing, is sentenced by Snyder to group therapy for abuse survivors. And runs smack into something she's not prepared for when another member of the group makes a suggestion. I don't want to spoil it for you, but it's the line right after "She looks me full in the face for the first time, and for a minute she reminds me so strongly of Drusilla I can't breathe."
"Witching Anya," by Darrin "Admiral" Colbourne. Also Buffyverse, but a really different one. Brief synopsis: there's an alternate reality in which Willow went really, really bad, and conquered everything. And then got lonely. And discovered, via cross-universe scrying, the human Anya. And... well. Want. Take. Have. If you ever liked Xena conqueror fic, this one's for you. Some great imagery, with the room of Cordys being a personal fave, though "I wrote somethin' nice" is good too. Standout funny/creepy line: "I even killed every bunny in my reality, just to make sure you'd never have anything to be afraid of." But it's the images that make this one a keeper.
"Star Whores," by Jefferson Morris. Ultraviolent, pornographic, scatalogical, and funny as all hell. Does for the original Star Wars trilogy what Bored of the Rings did for Tolkien. Too many great lines to quote, but my favorite bit may be the strip poker game from part three. Lando has lost badly, which means he's going to get up close and personal with all the other players. Including Chewbacca.
Lando groaned. "Come on, Solo. Gimme a break. What about my little maneuver at the Battle of Tanaab? Isn't that worth a reprieve?"
"Have you forgotten about your 'little maneuver' at the Orgy of Mytus VII?"
Lando rolled his eyes. "That was a long time ago, I'm sure everybody's forgotten about that by now."
Fett piped up. "Mytus VII? There's no such planet."
Han stuck his finger into Lando's ass, loosening it up. "They changed the name to Mytus VIII after the Orgy. Too much bad press."
(I'm also fond of the Boba Fett/Darth Vader exchanges: "What if he doesn't survive?" "Then he'll be dead. And two plus two is four. Anything else need clearing up?" And one character's description of a delightful activity: "It's like rolling in an Endorian meadow at daybreak, except you don't have to keep stopping to shoot those little bear things.")
Edit: I just realized that the version I linked to may not be all Morris: the archived version I have ends with part V, so I don't know if Morris actually wrote the later chapters on the page linked or if somebody else used his name.
Curious to see what sticks: I remember Celli's line because it's really dramatically effective; Admiral's images, because they're so vivid; and a lot of Morris's bits because they're fall-down funny.