The ratings for Darker Than Black from 2007 seem to get better as the season progresses, with an upward trend in ratings. The bingeable rating would be 80.
Best Episodes
8.8
S2 E14
OVA: Gaiden Part 2
8.8
S2 E16
OVA: Gaiden Part 4
8.5
S2 E15
OVA: Gaiden Part 3
Worst Episodes
7.1
S1E7
The Scent of Gardenias Lingers in the Summer Rain Part 1
7.1
S1E3
A New Star Shines in the Dawn Sky Part 1
7.1
S1E8
The Scent of Gardenias Lingers in the Summer Rain Part 2
Best Episodes
8.8
S2 E14
OVA: Gaiden Part 2
8.8
S2 E16
OVA: Gaiden Part 4
8.5
S2 E15
OVA: Gaiden Part 3
Worst Episodes
7.1
S1E8
The Scent of Gardenias Lingers in the Summer Rain Part 2