When Should It Have Ended?

People who follow me on der Lederhosen are no doubt aware that I have been critical of the past few seasons of Arrow.  (Having finished this season, my thoughts are "I'm actually insulted by the season finale. I'm only sticking around long enough to see who lived through the bullshit cliffhanger -- probably everyone -- and then unless I'm given a damn good reason, I'm out.")

With that in mind, let's play a little game called When Should They Have Ended The Series?

Series I Have Watched

Arrow: At the end of season 3, when -- for the first and only time -- Oliver and Felicity are happy, driving off into the sunset. Not only is it a happy ending, but there are NO dangling plot threads to be resolved!

Babylon 5:  Season 4, with the season 5 season finale as the series finale. Admittedly, there is lots of good stuff in s5, but the season was slow to start (what with having tied up all the plot threads at the end of s4, thinking they wouldn't get renewed) and did we really need Byron the angsty telepath?

Battlestar Galactica: Season 3, episode 4. This is right after the fleet has escaped from Cylon captivity on New Caprica, but before the start of "Starbuck kills herself, then inexplicably comes back" and "Part of the crew are secretly Cylon". Yes, plots are never resolved this way, but to be honest, some of them (Starbuck) were never resolved anyway. 

Blindspot: 10-15 minutes before the end of the s2 finale, when they've wrapped everything up but before they introduce the "2 years later" lead-in to next season. (I am aware this is a bit presumptuous as s3 hasn't even aired yet, but the lead-in to next season just screams "Bullshit relationship drama between Jane and Kurt."  And the magical DNA box & glowing tattoos just peg my WTF meter.)

CSI: Season 8 episode 7, with Sarah leaving the show. She joined the show in the first episode, so her leaving the show is a natural end point. 

Chuck: At the end of season 4. Again, loose ends are tied up and everyone is happy. 

Flash: I really want to like this show, but honestly I don't think I can take more grimdark. I loved the first season but I don't think I can take more gloom and doom.

Heroes: The end of season 1. I don't think anyone will dispute this. 

Highlander: I never finished this series because when it aired in the 90s it was syndicated, and the channel it was on decided to move its schedule around and air it in the middle of the night. That said, either the end of season 3 (resolving the Kalas plotline) or the first episode of season 4 (where Duncan returns home to Scotland) make a good end for the series. 

Lost: Considering the hot mess that this series became and how damn near every plot line was entangled with every other plot, I'm not sure there was ever a good place to end it short of "Never start watching in the first place".

Mythbusters: Whenever the build team left (end of season 11, I think?), because their departure seemed to suck all the joy from the show. 

Sleepy Hollow: Season 2, epsiode 11, "Akeda", aka the midseason finale. It wraps up the entire Moloch storyline and neatly avoids all the Katrina crap. 

The Walking Dead: When the the survivors reach the Alexandria Safe Zone (s5 e11). The gates open, Rick hears the sounds of children's laughter, and he just relaxes. It's reasonable to assume that everyone will be safe and we completely avoid all the stupid emotional manipulation and killing characters for shock value (other than Tyreese, whose senseless death -- and I will fight you on this -- is where the writing began to go downhill, with characters killed off purely for shock value).

Warehouse 13: Certainly no later than s5e1, which wraps up the previous season's cliffhanger without delving into the ridiculous "Myka and Pete are suddenly in love, just to make the shippers happy) and quite possibly sooner.

Series I Haven't Watched, But Have Been Told Went On Too Long

These suggestions aren't from me. 

24: Season 1. 

Gargoyles: Season 3. 

Millennium: The second season ended very apocalyptically. It should have ended with "Did the world end or not?"

Prison Break: The end of season 2. 

Sons of Anarchy: Season 3. They should have dumped the ridiculous Oirish side-quest and moved the major plot points from seasons 4-7 (which we all saw coming about three episodes into the show) up instead.

Supernatural: Season 5. They stopped Lucifer and the Four Horsemen of the Apocalypse. Heroic self-sacrifice. Natural conclusion. Cut the scene of Sam watching Dean and you have a wonderful 5 season arc.

The X-Files: Season 7. 

What are your thoughts?