You, my friend, have good taste. Let's see what I can offer you.
I'll probably leave some out, not because they aren't good, just because there are so many.
GAMES
SummerTime Saga (Although there are complaints about its "Tech Update" it is still one of the highest quality games.)
My Dorm (It doesn't do anything revolutionary and yet it's very good.)
My New Family (If any game deserves the "cult" label, it's this one, oldie but goodie.)
Between Humanity (Just... try it, it's not for everyone.)
Ethernum (I'll be honest, I haven't tried it, but I'm looking to do so.)
Once in a Lifetime (One of the best and also deserving of the "cult" label)
Cosy Cafe (I played it a little, stopped for personal reasons and it eats me up inside not having time.)
Funkelregen (I'm not a fan of sci-fi, but this one is good enough for me to enjoy.)
The Inn (If you hate NTR like me, you'll applaud this one.)
World's Crossing Academy (I had low expectations and now I'm eagerly awaiting an update.)
MurMur (Another of excellent quality, not recommended, mandatory.)
The Headmaster (Based on spanking kink, but it doesn't matter it's very good overall.)
Stormside (I haven't played it, but I've heard a LOT of good things about it.)
That New Teacher (If you put Ecchi Sensei and The Headmaster together and add some well-done humor, you have this great game.)
Friends in Need (You'll probably like it, although it might be annoying how the decisions work.)
The Assistant (I played it a while ago, it took me a while to find it and it's better than I remembered.)
GAMES +
My Daugther Forever (Classical structure AVN.)
Libertine (A "heavier" AVN in terms of its story.)
Insexual Awakening (A 2D game that practically everyone has played for good reasons, it's very good.)
Insexual Awakening 2 (Sandbox style, but well done. It's not a direct sequel, but it's based on the same universe.)
Little Green Hill (Personal favorite and for me, spiritual sequel to Ecchi Sensei.)
Found in Translation (Another classic AVN structure, very good.)
Such a Sharp Pain (One of the most popular and for good reasons.)
Money or Morals (One of the most promising, though now on hiatus. Its developer is burned out and doesn't feel the same passion as at the beginning.)
More Than A Daughter (Graphically excellent, although slower than a quadriplegic snail.)
Teacher's Pet (It also looks great, but its development is slow.)
Crime of Slave (This one looks promising, not much content yet.)
Radiant (Undeniable quality, although there are complaints about the speed of development.)
Diary of my Perversion (Pretty good and highly recommended.)
Corrupted Love (Famous for its troubled development, but in the latest updates it is noticeably more stable.)
I'll be using this post as my personal checklist to keep track of the good games I've played.