I'm honestly surprised that father/daughter is winning against mother/son. Feels like I see so many mother/son games.
That being said, father/daughter is the goat. I do love granddaughter/grandfather too though since you can still have a good age gap with the girl being a bit older.
Father/daughter tends toward loli/hebe/teen lovers, who hang out here. Mother/son is MILF lovers, who mostly hang out on F95 where ten thousand games that stroke that particular fetish are readily availible. Even some straight shota stuff can be found there, since they have a huge double standard.
Twincest is wincest. Cousin relations are like the half-assed incest fetish alongside stepfamily that may as well be strangers and don't see each other as family.