I feel like Dawn and May are often locked into this friendly rivalry with romantic tension box, but I see more writers stretching that lately. The classic road trip fic is a huge favorite, obviously—two coordinators traveling together, sharing hotel rooms, that forced proximity just writes itself. Lately I've noticed a lot more post-Journey stuff, where they meet again years later and have to figure out who they are outside of competitions. There's a specific angst flavor where one gives up coordinating and the other doesn't, and the guilt/resentment simmers.
Also, the rival's sister trope gets flipped on its head a lot. Instead of it being about Max, it's about Dawn being the one who truly understands May's pressure from her dad, because Wallace put similar expectations on him. That shared burden from authority figures creates a quieter, more mature bond than the early fics where they just bickered over contests. I'm less into the ones where they're instantly attracted; the slow realization of respect turning into something else hits way harder for me, probably because their canon dynamic already has that foundation.