I like more of the Father/Daughter relationships and the Brother/Sister relationships although the incest games I've played are more focused on Mom/Son.
Father/daughter, would never with me cuz autism intresting to be struggling as a single father.
brother/sister growing up and sneaking off into each others rooms while parents don't notice
mother/son need a parental figure to teach and nurture. love is very confusing to me.
For me the list looks something like this: Straight pairings:
Mother / Son
Aunt / Nephew
Father / Daughter
Brother / Sister
Grandmother / Grandson
Gay pairings:
Mother / Daughter
Aunt / Niece
Sister / Sister
Grandmother / Granddaughter
Father / Son
Grandfathers and Uncles don't do anything for me, so they don't make any of the lists. That said, Mother is and will always be top of the list. MILFs are just way too good.