I am a sucker for Harry Potter kinky fanfic. My favorite story is here:
https://archiveofourown.org/works/58...pters/13453234
I really love anything with Hermione as a sub. Harry Potter is a rather whiney character as a whole, so I like to avoid him when possible. Draco is also fun as a sub. I would definitely read a McGonnagal story as well.
Best of luck!