Parental Love
My Sweet Neighbors
Babysitter - This game is awesome, blows DmD out of the water. Christine, the niece who you are after is amazing, and I am proud to call the writer of this game a friend
Sisterly Lust - This game is pretty great, allowing you to harem your sisters and mom through romance. Its a lot of fun and each character has their own personality and motivations.
Blooming love - this is a sweet yuri tale of two sisters. Its a little silly how virginal the ladies are, but its so sweet that I love it.
Dual Family - I'm gonna be honest, you'll either love this game, or hate it. The dev has written a great story that stands on its own while simultaneously satirizing and exposing the darker side of incest games and their creepy gameplay. Seriously I love this game. However its so depressing and has very little sexual content, so a lot of people don't like it.
those are all nearly identical to DmD mechanically
Other VN, only slightly different mechanically but still not simulators or rpgs
I Love Daddy - This is my favorite completed game. Has 10 endings that all lead to learning more about the world than you knew previously.
Depraved Awakening - This is one of the 5 games I hold on a pedestal of storytelling, a Noir Detective Story with a sexy story to tell.
Wicked Choices - Also on my top 5 pedestal, this game is my second favorite fantasy game on this site. The writing is top notch.
Intimate Relations - Ptolemy, the developer, is one of the better writers of female characters with their own motivations.
Soul of the Paintings (actually this one could probably go up with those at the top)
Dreams of Desire - Use magic to turn your family into your personal harem in this story of intrigue and suspense.
Sister Sister Sister - Learn from your older twin sisters how to hypnotise and fuck women, with the ultimate goal being your own twin sister.