I can toss a few in the rec bucket for completeness.

>Low Rung Researcher
>Really well written, super regular updates. Captures the feel of a poorly run SCP-lite research lab really well, and the QM does a great job balancing tension with some more lighthearted elements. QMC is funny in a sad way and often vice versa.

>Local Lord
>Straight take on a medieval isekai that somehow manages to be both believable and absolutely fucking hilarious. Writing is suspenseful and genuinely very gripping. MC is a french noble who is so racist he assumes italians are literal goblins. QM is also french I think, but the based good kind.

>Dark Quest
DemBones is kinda like a winemaker - his stuff just gets better over time. I found it a bit more structured/fantasy esque than Bones quest (the original), which is great in my book. Great solid semi light-hearted fantasy with really lovable characters and soulful art.

>Monster Girl Facility
The scariest part of the facility is that it has real women in it. Good, suspenseful quest with a shocking amount of effort and lore put into it - QM is super dedicated and it shows in both the writing and the worldbuilding. Amazing on a binge, and it captures the feeling of being lost in a huge facility really well. Girls are cute too, I think.

>Cambion Quest
I still have this one penciled in for a review potentially. Solid fantasy quest with a good mix of action and character development/interaction. Interesting mix of settings - most recent updates have felt vaguely like a cultivation-lite. Some lewd elements per Reptoid's style; MC is a futa so make of that what you will.

>Pokepocalypse
I don't usually read much fanfiction, but this one honestly stands out. Kind of like Local lord, this genuinely does a great job capturing the premise - its written more or less exactly as how you would imagine a 1800s era dude to write a pokemon invasion. Cool characters with a nice overarching plot. MC is resourceful and fun to follow.

>Olympus Incarnation
I want Ate to marry me.

>Drowned
This one is coming to a well deserved conclusion, so I feel like its worth mentioning here still. Quest is very long and dialogue-heavy, but the setting is very unique and I genuinely haven't seen much similar to it outside of like a few really niche games. Lovable/hatable main character that "enriches" the story considerably with her antics, and a bunch of neat supporting characters with "interesting" personality quirks. If you wanna follow it for the end, which I recommend, the QM has recaps that do a pretty god job getting you up to speed (though it'll still take a long time).

>Nemesis Quest
Kind of like a mid 2000s high school emo album in quest form. Writing is good, hyper edgy plot in a way that seems almost oddly comfy/benign. Enjoyed the first two threads overall, though not a huge fan of the incest elements for hopefully obvious reasons.

>Solstice Quest
Sci-fi quest with a flaky, unreliable QM. Do not recommend reading.