Weeds — Currently: Eight Seasons.
When It Should’ve Ended: “Weeds” should’ve bowed out a long time ago, after the original conceit had been exhausted, when Nancy stopped being a suburban housewife who was a small-time dealer trying to keep her family fed. The series should’ve ended with the finale of Season 3, after Nancy burned down the town of Agrestic. The series closing scene should’ve seen Nancy and her family walking away from the burning suburbia and heading into a new life. We never needed to see that new life.
Dexter — Currently: Six Seasons.
When It Should’ve Ended: In the finale of Season Four, Dexter murdered the Trinity Killer then found out that the Trinity Killer had murdered Rita. The series should’ve ended there, with the police department arresting Dexter and charging him for her murder. He would’ve received the death penalty, and there would be some poetic justice in the fact that Dexter is killed for the one murder he didn’t commit, plus it would’ve allowed John Lithgow’s brilliant Trinity Killer to appropriately get the best of Dexter from the grave.
The Office — Currently: Eight Seasons.
When It Should’ve Ended: Episode four of seasons six — Jim and Pam’s wedding — should’ve been moved back to the season finale of season five, and that’s where it should’ve ended, capping a strong series with an uneven final season. This should’ve been the end of the series.
The Killing — Currently: Two season.
When the Show Should’ve Ended: At the end of the first season, when they SHOULD’VE SOLVED THE GODDAMN MURDER OF ROSIE LARSEN.
Glee — Currently: Three Seasons.
When the Show Should’ve Ended: Midseason finale of season one. “Glee” should’ve been a one-season 13-episode series that ended at sectionals. If it’d been canceled then, people would’ve remembered so fondly that movie rumors would surface every other month, the Internet would never forgive Fox, and the show might’ve gone down as one of the best canceled-too-soon cult shows.
Grey’s Anatomy — Currently: Eight Seasons.
When the Show Should’ve Ended: At the end of season two, when Denny died.
30 Rock — Currently: Six season.
When the Show Should’ve Ended: Season four, after Kabletown bought NBC.
Fringe — Currently: Four Seasons.
When the Show Should’ve Ended: At the end of season three, when Peter disappeared and was completely forgotten about. That would’ve been a wicked cool way to end the show.
The Simpsons — Currently: 23 Seasons.
When the Show Should’ve Ended: After the eighth season finale, before Mike Scully took over as executive producer.
True Blood — Currently: 4 Seasons.
When the Show Should’ve Ended: After the pilot episode? Or maybe halfway through it?