As for me...
SAMURAI JACK!!!!
Why? Because It is a masterpiece of animation and I like the fluidity of the motions of its animations, the simplistic character designs, and the lack of a thick, black surrounding outline, and everything else that made it such, like its highly cinematic style and highly stylized outline free masking based animation, and also because of the music, the backgrounds, even the vocal talents of characters like Jack and Aku, the split screens and even the multiple angles and multiple closeups in the same image.
It also had a lot of lighting and mood and atmosphere and very little dialogue. Too bad that Samurai Jack is a good show whose life is cut short in 2004 without a proper ending despite its popularity, and it is this, along with the abrupt cancellation of Sym Bionic Titan that leds to Genndy Tartakovsky doing Hotel Transylvania at Sony.
My suggestion for how would Samurai Jack end properly is this:
Samurai Jack's hope to find the time portal so he can return to his own time and do the killing blow to the future that is Aku finally became a reality, when Jack and The Scotsman meets a heroic, if pretty and lovely girl descended from Samurai Jack who is as mighty, brave and noble as a warrior, as she is young, fair, and beautiful as a maiden (and physically based on Dee Dee's Asian friend LeeLee from Dexter's Laboratory), and according to a prophecy, the girl descended from Samurai Jack holds the key to finally help her great ancestor so he can finally find the time portal, so he can "return to the past and undo the future that is Aku". Eventually, The three of them and an army of good engages Aku, his minions and the most massive army of evil ever assembled in a great epic titanic battle that culminates in Jack jumping into the time portal and landing right smack into Aku in his castle right where we left off at the end of the first part of the premiere movie, and Jack finally manages to do the final killin' blow to Aku, destroying him and undoing the destruction that Aku has wrought since Birth of Evil, and it should end with Jack ascending the throne and starting a new family in the beautiful, peaceful world he had in mind, and thus the prophecy has been fulfilled by Samurai Jack and the warrior maiden who is descended from him.
So, what do you think?
Time of answer I'm looking for. Detailed and more deeper than just "Because it's a great show!" type answers. You mentioned Sym Bionic Titan. Why? And how would you end it?
I actually just thought of Spiderman TAS.
Why? Aside from being a great show, I think it's the best portrayal of Spiderman in animated form. The costume, voice, the way the city and buildings looked. Really loved the plots and the way villains were introduced. Only downside to the show (for me) was that many times, there were re-shots. But it's understandable as it's due to reduce budget costs. According to John Semper (or however you spell his last name), Season 6 was supposed to see Spiderman finding MJ in limbo?
My ending: He and Madame Web would go back in time to find the real MJ. They would find her in a time period where Uncle Ben was still alive in Peter's dimension rather than having him go to the Spider-Carnage clone's just to see him. So it'd have to be a time before Ben was killed, yet after Peter got his powers after being bitten by a spider.
Note: I don't remember how Ben died in the show so I am basing the Ben being killed after Peter got his powers part of my ending from the 2002 movie.
So he'd find her. Her memory would be gone for a while after being stuck in time for so long. But it would wear off and she'd remember him. The villains, who ended up in this time would be Carnage, Hobgoblin, Green Goblin, Doppleganger Spiderman (he was in Maximum Carnage) and Venom. Kingpin would be here too. But Smythe wouldn't be with him (yet) as his father would still be alive. Their reasons for being villains: Carnage would just be carnage. Doppleganger Spiderman would just be this big unstoppable thing who wrecks havoc for no reason. The goblins would just want money for their own personal gain and would eventually join up with Kingpin. Rhino and Shocker would join them too for money. Since he can't be with Ashley anymore, Eddie's anger over that made him don the symbiote again to become Venom.
DD would be here fighting to good fight against Kingpin (in a continuation of sorts from The Man Without Fear episodes) so he'd be allies with Spidey here. Doctor Strange would sense Spiderman needs help and with Wong, he'd help out too. With this group of villains, he needs all the help he can get! Black Cat, Iron Man and War Machine would be there too (Morbius and Blade would be still be trying to reach Blade's mother (They're not seen here except in a flashback as Cat tells Spiderman, when he asks her when she came back to NY, which eventually reveals they're successful at that.)
Venom and Carnage are dealt with first as they are seen as the biggest threat (aside from Doppleganger.) Venom and Carnage can't get along as Carnage is too crazy to really get along with anyone so he turns on Venom, who as a result, joins Spiderman although he really isn't a hero and is just getting back at Carnage. So Carnage is no more and Cassidy ends up in jail. They plan to do the same to Venom. But Spidey feels they could use him to take care of Dopple so they reluctantly keep him and Dopple, after a valiant effort, ends up in the Hudson River. With him gone, Venom/Eddie feels there's nothing for him now so Venom's no more and Eddie decides to go to prison since it can't be any better in the world since Ashley's not there.
Kingpin finds out himself that the goblins were stealing from him and once they know that, they turn on him and take whatever money they can and leave as far as they can. That is, till Iron Man and War Machine take care of them! In the last fight, DD finally gets the one on one with Kingpin he's wanted and wins it. Kingpin (and the goblins) end up in jail. Spidey and his allies thank each other, saying how great it was to work together, etc and go their separate ways after Spidey takes a picture with them.
Spiderman and MJ talk in their home and he tells her that he wants to spend time with her, not spend time crime fighting. MJ asks him what is he trying to say, exactly. He say he no longer wants to be Spiderman and if it wasn't for that costume, they would have been married by now. She asks if he's sure about giving up his powers and brings up the possibility of villains. He says yes and let the cops handle the trouble. And then says, he's done. So he gives up being Spidey and marries the real MJ with everyone (Jameson, Robbie, May, Ben, Harry, Liz, Flash, Debra, Curt Conners, etc being at the wedding.) - this portion of the ending is kind of like the ending to Rises without the marriage stuff, being in a restaurant and Bruce openly saying he's done.
Notes: Lizard/Scorpion/Dr. Octopus doesn't exist here as those villains didn't travel here through time. And because Conners' arm wasn't damaged yet and Otto Octavius and Gargain, while here, were still normal people. As for how the characters that did travel through time (aside from Spidey who had help from Madame Web and Strange/Wong who used mystical powers), the others used that time portal device (apparently Kingpin still had a hold of one when everyone else thought there was none left)
I know this is unlikely to happen. But just using my imagination. What do you think? I'll come up with a more real ending when I come with it. Haven't seen the show in a while so gotta go back to that first.
Other shows....King Arthur and the Knights of Justice, Mystic Knights, Beetle Borgs, VR Troopers, Knight Rider, Batman TAS, JLU. I'll get to the endings for these too.