Some nice, smooth, consistent quality. Better Call Saul was in my opinion pretty consistent. Single season anime is almost always consistent, like My Dress-Up Darling or Terror in Resonance.
Not dragging on longer than the series needs to seems to be a key point.
I really liked Parasyte but I think it should have ended one episode earlier. The last episode felt like an entirely different show, and the ending of the second to last episode (Parasyte Dude heading back to town after the big fight) had an uncertainty that I thought would have been a good ending to the series.
Yep, the entire series was pretty unhopeful for the fate of humanity, if it ended more like The Thing it would have been more keeping in tone, but idk maybe 80s manga had to have hopeful endings