1. OMG that opening sequence of Mycroft chased through his house by Insane Clown Invaders! The Umbrella-sword-pistol!
2. Dead!Moriarty! (jesus christ, I hope that means the end of him)
3. Sherrinford is a place not a person (+1 for Dee); Sherrinford isn't the sibling (+1 for Dee); this on top of the sibling being a sister is the complete trifecta of as close to squee as my misanthropic, black little heart of capable of
4. Mycroft being willing to sacrifice himself for the mission because he knows losing John would destroy Sherlock utterly...I haven't cried while watching a TV show in about 25 years, but that got me very, very, very close (and typing it is getting me even a teensy bit closer)
5. Everyone lives! Even Eurus.
6. Mrs Holmes calling Sherlock the "adult" and Mycroft's reaction; OMG another stab to the heart (and self-regardingly, another little boost to my Holmes family headcanon)
7. And yeah, they've "left the story in a good place" alright; logically, you knew they had to because they haven't signed up for a 5th series yet, but giving Mary the last word was a bit annoying
8. The most fan-service-y episode yet. Every major ship seemed to get their token little moment to cling onto, which I think is a bit weird. *shrugs*
More once I watch again tonight!