Marla's standoff with Mrs. Booth. After Marla gets stabbed multiple times by Mrs. Booth, Booth is shot by Amy, and then Marla grabs Booth's hook and jams it in the back of her head to finish her off while screaming an epic war cry.
Marla: You are nobody's mother.
Mike putting an end to the threat of Candle Cove once and for all: he lets Eddie drag him into it, and distracts him with a card game they never finished, long enough for Marla to kill his body, cutting off Eddie's connection to the real world.
Jules taking a level in badass following the Time Skip, spending an entire year tracking down The House and marching in there armed and dangerous, determined to not let anything stop her from saving Margot.
Jules escaping from and destroying The Orb after an entire season of it tormenting her. After doing so she only spares the briefest of moments pondering on just what it is, before deciding to forget about it and focus on saving Margot.
Seth's incredibly satisfyingKarmic Death after Margot releases his "family". Afterwards, his hollowed out victims descend on his corpse, with the clear intention of disposing of what left of him.
Margot coming to terms with her father's death and finally leaving The House with Jules.
Zoey eating parts of her own leg rather than succumb to the temptation to eat the Peaches' victims.
As much of a monster as Robert is, and as satisfying as it is to see him shot a moment later, his "they don't matter. If they did, you would have looked for them" taunt is deeply satisfying to anyone who was frustrated at the apathy Luke and his partner showed towards Izzy and her mother's disappearance, and their willingness to let them fall through the cracks.
The truly amazing (and far too short) scene where Pretzel Jack fights against Tall Boy. He uses his contortion to his advantage, ragdolling to dodge a swing before backflipping away, snatching Tall Boy's weapon away from him and sawing his head in half. This is all scored to 80s synthwave.