Justified is my all time favorite. But they ended it perfectly. That softened the blow a little bit. Although, I've always felt that a spinoff series on Tim Gutterman would be excellent.
The show I regretted the most when it ended was Longmire. The last season or so, they really started to flesh out the characters of Matthias and Nighthorse. I really would've liked to see that continue. I really liked how Matthias changed over the course of the series.
Yellowstone is the only series I've sen to approach the quality of writing of Justified. But they pissed me off this season with such a humungous cliff hanger. LOL. I cant wait for next June!