So I stumbled across this amazing JJ/Vision dynamic a while back, and it honestly made me start digging for more crossovers. You’d think they’d be everywhere, but a lot of Marvel fic can get pretty Iron Man or Cap-centric, you know? Honestly, your best hunting grounds are Archive of Our Own and Fanfiction.net, obviously, but the trick is in the tags. Just searching 'Jessica Jones crossover' is gonna pull up a lot of Daredevil stuff, which is fine, but it’s not quite the same. Try pairing her name with other characters in the tags—like 'Jessica Jones & Carol Danvers' or 'Jessica Jones & Peter Parker'. The '&' is for gen, '/' is for shipping, so that helps narrow it down.
I’ve found some really interesting ones where her cynical, hard-boiled PI style clashes with, say, Spider-Man’s quippiness. There’s a writer who does a series where Jess gets reluctantly pulled into consulting for S.H.I.E.L.D. post-'The Defenders', and her interactions with a world-weary but still hopeful Steve Rogers are fantastic. The tension isn't romantic; it's this ideological friction between her bruised pragmatism and his unwavering idealism. You get these great moments where she’s just bluntly telling him his moral code is naive, and he quietly proves her wrong through action. That kind of character-driven clash is what makes a good crossover for me, not just punching bad guys together.
Don’t overlook smaller fandoms or specific comic runs either. I read one where she crosses paths with Kate Bishop from the younger Hawkeye comics, and their dynamic as two very different, stubborn women trying to solve the same case was hilarious and sharp. Tumblr can be a good source for those, actually. People will sometimes reblog snippets or link to their AO3 posts. The key is patience; you might have to sift through pages of results, but when you find a writer who really gets her voice, it’s worth the hunt. I just wish there were more with characters outside the street-level sphere—a Jessica and Shuri team-up would break my brain in the best way.