Granddaughters can also be loli's.Dad/daughter and then Mother/Son.
Dad/daughter wins because it tends to be lolis, and they always win
The Visit! Possibly the first ever h/game I played. Never gone back to it, though. Faster and hotter games out there rapidly showed up.Best Sister and Mom is "Monkey Business" and I will not be convinced otherwise. Less so of a harem game, though.
The Visit was also top tier.
Desert Stalker is good.
Power Vacuum can be okay at times, if you can stand the humor.