Ciato

I got Dimitri/Byleth (obviously very sweet S support), Felix/Annette (which is just so darn cute and I love everything about it), Sylvain/Ingrid (not too happy with this pairing overall, would have preferred Mercedes honestly), and Doro/Petra (which is excellent).

I have Annette as my Dancer on Church Route. It works pretty well because she has the stats for it, and I recruited her a little too late to make her into a really serviceable unit otherwise (and I love her and she is adorable). She is actually not bad on combat, though; her accuracy and Excalibur are still sometimes useful. Doro was my Dancer on BL. Because she has so many tools already (Meteor and Physic), it felt sub-optimial. Annette has been a better fit for the role I think,

I don't want to read too much into author intent here, but Sylvain does not really like women on a personal level very much, as demonstrated over and over throughout his support list. His 'love for women' is a front for his deep-seated issues with women and society at large. It is not a stretch based on his development that he could potentially conclude that he would prefer Felix (who really gets him on a personal level) over his shallow pursuit of women. (Or not, depending on your ending!)

I married Dimitri first playthrough, not sure who I will marry with M!Byleth on second (Church) route though. Maybe Hilda?

I feel sorry for Sylvain (it sucks to not be able to read if people genuinely care for you or it's just a way to gain access to resources), but he is also abhorrent for his behavior toward women (even if it is a defense mechanism). His beefs about Fodlan society are justified but he is suuuper privileged within that structure (and in one support, he even acknowledges that his brother had a way worse life. Mercedes?). His behavior is very bratty and reactionary. I think a lot of his supports are really nice; I really liked Mercedes' because you really get down to what he stands for and she is able to carve back a lot of his nonsense. In many of the other supports, he seems to be incapable of actually being sincere towards women in normal conversation and even when he tries (Lys B support) he fails at it. I think that is why they chose to give him a lot of B supports; he's just not that great at genuine interaction with women because of his poisonous relationship with them. Also, post-timeskip he seems to be fairly depressive and uninterested in much of anything; he is tending that way pre- but he seems even less engaged/motivated post-. With that being said, I think Edelgard/Sylvain would have been an excellent support because they align so much on core values. And man does he sparkle in some of his scenes. Even if he's probably faking it.

Elincia would be a great Mirage to have. :)

Most of my favorite people to play (Lucina, Palutena, Dedede, Megaman) are all servicable, although I have like many people in this thread concluded that Zelda isn't worth using. I'd love to see the HW Zelda design in the game instead.