I'm pro OCs, Different Mediums, Established CR etc.
Incest: Canon; Carson/Nancy, Ryan/Nancy, Everett/Nancy. Or AU. Can be father, step father, foster father, sibling, cousin, uncle etc. Nancy wasn't raised by her biological family and her bio family doesn't know she exists so there's plenty of option for accidental as well. Or accidental but then they know and can't make themselves stop.
Power Dynamics: Cop arrests Nancy. Nancy held captive. Nancy blackmailed for sex. Nancy and a Teacher/Mayor/Friends Father/High Powered CEO Type.
Omegaverse: Nancy as the unexpected Omega is always a plus. Knotting, Heat Sex, Mate Bonding, Breeding/Impregnation. Nancy is constantly trying to suppress her Omega instincts so when she does go into Heat, it's intense.
Interspecies: She's used to the supernatural so different doesn't freak her out. Also open to the potential for Dub-Con/Non-Con.
Villains: Nancy has a knack for investigating things she should leave well enough alone. I'm always keen to explore everything from rough/hate sex, dub-con, non-con, Stockholm, brainwashing, experimentation.
Keeping it Real: Sometimes you just want the simplicity of throwing two characters together and seeing what happens. I'm always down for straight up, here are two characters and a setting let see where it goes, shenanigans.
Sexual Awakening: Especially with younger Nancy, I'd love to explore some of those early encounters for her. Whether it's with a far more experienced partner or somebody as clueless as she is. Things getting out of hand, neither side really thinking it through.
Threesomes (moresomes): I really like the idea of Nancy being with a couple. Somebody for them to share or even guide. That said, always down for other threesomes/group scenarios as well.