No End House and Russian Sleep experiment are, just from a story perspective, probably my two favorites, with Left Right Game a bit below them. The first two are short and sweet, work really well as short stories and I don't have any major complaints.
Left Right Game, especially the first half or so, really hits that liminal horror that I love, and I'm a sucker for stories about going somewhere with a focus on all the areas in between rather than the destination, so just traveling through an ever evolving liminal space is something I desperately crave. It does have some problems, probably the biggest of which is that the ending is my least favorite trope, but I will give it credit for being the best implementation of that trope that I've experienced (that trope being confronting an omniscient being who won't explain things because the mortal won't understand, not the redditor arriving at the tunnel, I didn't mind that)
Honorable mention to Ted the Caver, it's definitely up there with No End House and Russian Sleep experiment, possibly even above them. A lot of these creepypastas really struggle with their endings and Ted the Caver fucking nails it
I also like The Showers and Penpal, but I don't quite love them. It could just be a failing on my part but I don't really get the actual showers. I honestly probably would have liked it more if it was just an empty, dirty room that you can just walk into by going through a door but it's much harder to leave because you have to go through all the weird, dark hallways, and as you're leaving the denizens arrive and try to drag you back in. For whatever reason having the empty room have showerheads for no reason just takes me out of it and makes it less spoopy and drags the story down far more than it should (not to say anyone's wrong for liking this one, it just bugs me personally for reasons I don't understand). The premise of Penpal is great but it just goes on a bit too long. Not sure exactly what to cut but I think it'd be better if it was trimmed down, and it has a weak ending like I complained about earlier
The worst is obviously Jeff the Killer, with The Thing in the Basement not too far above it, but these are actually my two favorite epsiodes lol, like Best of the Worst but with shitty creepypastas
The Stairs in the Woods does seem like a lot of fun but they didn't read it and I haven't read it so I can't comment on it as a story
Tommy Taffy I disliked, it was just way too try-hard, in a bad way. The rest I don't have any real thoughts on besides "They're fine-ish but weak ending"