Broadchurch (Seasons 2 & 3) - Back in 2013, we watched season 1. While excellent, it was very intense, centering on the death of an 11 y/o boy in a tight-knit English coastal town. So much so, that when series 2 aired, we opted to not continue watching.
In the last weeks, we circled back to binge thru season 2 & 3 in succession. These were just as intense as the first and reminded me how much I love Olivia Coleman's work. Definitely not for the faint-of-heart, or a casual watch. But these were the blueprint for many similarly-themed series over the last decade.