Looking over my directory of partially-written bad fanfics, I see:
- a Batman fanfic where Batman is forced to work together with Slade (the Teen Titans villain) and his team of Bad Guys
- an Indiana Jones and the Crystal Skull fanfic where Mutt turns into a Timothy Leary dropout druggie in the '60s
- a Metajets fanfic where I kill off several named characters and put others out of commission
- a Slayers fanfic that resulted from several iterations of messing with the universe until it was set 20 years in the future and dealing with the heros' kids, and an accompanying outline for a story that destroys that universe another 50 years in the future
- a Smash Brothers fanfic/parody where the fighters are recruited by a guy who messes up universes for fun
- an outline for a Stein's Gate fanfic that puts Okabe in the hospital and makes Kurisu the lead
- a Star Trek:TNG fanfic where the Federation gets in a civil war, and Picard and Riker end up as opposing captains
- a Transformers fanfic with a little bit of intellectual insight into geopolitics, no tits, and fewer explosions
- [Edit Sep 10] and one more I haven't begun to write: a Garbage Pail Kids fic that patterns the dolls after stereotypical 1950s gangbangers, removes all the grossout humor and replaces it with slapstick, and makes the dolls one faction in a great Toy War involving parodies of Barney, Pokemon, GI Joe, He-Man, Green Army Men, and the Care Bears
My imagination doesn't like to stay within the bounds of an existing universe. I don't write episodes. My tendency is to do something grand with it that changes how the universe is arranged.
Bonus: have some parody ideas that I haven't written but I can tell the whole joke in one paragraph.
- Metroid: rough brunette '80s Samus wakes up from cryosleep and mugs sexy blonde Zero Suit Samus in an alleyway, then takes her armor back
- Touhou: Komachi and Reimu set up a racket where Reimu hunts and kills wealthy criminals, Komachi ferries their souls across the Styx to meet her work quota while charging them a significant fee, and then Komachi makes a donation to Reimu's shrine. Then the loli vampire Remelia appears in Reimu's room at night to warn her that pedophiles are *her* business.
- Touhou again, crossed with End Of Evangelion. Enough said. No, I can say more. The invaders are the TF2 characters, then I ran out of ideas so let's redo the Twilight Zone doll episode with Shang, Pyro, and Engineer.