Harumaki

The Face Beneath (Caspar/Mercie), I love how bittersweet it is with the ending and it made me like Caspar, not to mention the rewards are great and I love the map as well. Some honorable mentions would be Darkness Beneath the Earth for some of the same reasons above and just because listening to Hubert's voice is always a bonus, Silver Maiden and Weathervanes of Fódlan just because I love exploring more of the relation between Gilbert and Annette.

Is there any point to getting support points with Jeralt?

Some that I haven't seen mentioned yet are Seteth and Flayn with Thales in SS, Gilbert and Annette from both times he's an enemy in CF (The one in chapter 12 is the same as the apparently unused one from AM) and Edelgard with Solon and Kronya in chapter 10. I can't exactly recall all of them, but I remember they were pretty neat. I'm also guessing Cyril might have one with Shamir in CF? He was reaaally close to the boss and I didn't want to mess with that.

Well, Edelgard is definitely the Rudolf/Walhart/Arvis archetype while VW and CF Dimitri is more like Michalis than Marth imo. I think the Pallardos technically count as the bandit twins? Maybe? And Judith/Gilbert/Rodrigue feel a lot like Lewyn did in FE4's second gen. Oh, and Hubert maybe counts as a Camus for VW, if only for helping the main lord's group somehow.