Considered making my own similar thread since I can also relate to OP when I made a spreadsheet compiling the 100s of games I've played from F95. I'll share some of the games I've kept in my higher tiers for gameplay reasons from said google sheets for now, enjoy!
S++
The two GOAT games that I spent 100+ hours on and will come back to a lot for the gameplay are in my mind:
Karryn's Prison -
https://f95zone.to/threads/karryns-prison-v1-2-9-64-dlcs-remtairy.33777/
Hyped for P-cup update soon, THE game of replayability and content if you wanna try diff builds etc. Gameplay and combat are the gold standard imo. Story and art is also top top top quality compared to most.
Tales of Androgyny -
https://f95zone.to/threads/tales-of-androgyny-v0-3-46-0-majalis.1643/
Always come back for a new playthro or two every few months/updates, lots of replayability
S-
A 3rd place Shoutout to Corruption of Champions -
https://f95zone.to/threads/corruption-of-champions-final-fenoxo.1719/
I was addicted to this back when it came out/just got finished waaaaaay back, easily spent 100 hours on it. Reading based RPG so can't recommend to most people though
A+
Other GREAT (gameplay) games that stand atop the mountain that I've played from on here are:
ErisDysnomia -
https://f95zone.to/threads/erisdysnomia-v1-02-above-a-damage-tile.121557/
Played 5+ hours, gameplay and animations are really fluid
Futaring -
https://f95zone.to/threads/futaring-v3-39-mofuland.3763/
Played 10-20 hours, good replayability of campaign due to gameplay
Heroine Rumble 2
https://f95zone.to/threads/heroine-rumble-2-v0-251-enlit3d.167418/
Played 20+ hours. It is in development and I'm hyped for what is to come. There is already a mod scene for it and so far the gameplay and customization is looking good. The Campaign is not as fleshed out as the first game, which I can also recommend checking out, even tho it is more flawed.
Creature Hunter -
https://f95zone.to/threads/creature-hunter-2-00-arumero-soft.2049/
Played 60+ Hours, Unironically played this an equal amount to some Monster Hunter games. You have to play on the hardest difficulty though and enjoy the grind/losing, it will feel like a Dark Soul-ish experience. Also really be into certain fetishes, I would not recommend this for everyone, a hit or miss for most. And don't play on easier/medium difficulties, then the game is really boring.
Last Evil -
https://f95zone.to/threads/last-evil-v3-0-1-flametorch.47693/
Played 10 hours. The greatest card game on here, tho the animations/porn is a bit meh. The gameplay is craaaaazy fun tho.
Demon's Sperm -
https://f95zone.to/threads/demons-sperm-v2-1-fullfrap.25099/
Played 5+ hours, really fun gameplay, dark souls inspired game. Very short, but can do a replay or two.
Secret Flasher Sereka -
https://f95zone.to/threads/secret-flasher-sereka-final-sheablesoft.170781/
Played 5+ hours. This is one of those games I'm hoping get some huge mod support, new levels, new content. The potential is there for so much, but the game is waaaaaay to short for how much fun I had with it. Almost felt a bit hollow once everything was completed (achievement-wise) in this one.
Some other notable mentions from lower A to higher B tiers I'll drop without links (some here will be very hit or miss depending on the person/preference):
Ayura Crisis, Key of Egg, Behind the Dune, Ariadne, FairyFighting, Wolf's Dungeon, Orc Castle, Scarlet Maiden, Strive for Power, Tamer Vale, Moral Sword of Asagi, Kamikaze Kommittee Ouka, Sneak in Desperada, Juuyoku no Jousai, the Fortress of Carnal Lust, Bible Violet, Alien Quest Eve, Elf Jail, Erotic Trap Dungeon (1+2), Lewdest Labyrinth, Imperial Gatekeeper, Dark of Chloe, Unholy Torturer(+dlc), Nako's Magic and the Monster of Pure Desire, MaiDenSnow Eve, Cinderella Escape(1+2), Widow in the Endless Labyrinth, Anthophobia,