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.
The Melancholy Of Haruhi Suzumiya.
Oh I forgot about Yuki-Chan side-series. That's a drop-off. I don't know then.