Warning the following has major spoilers.
Top Ten Worst Endings in Anime:
10. Gun Frontier. It ends with story unfinished, bad guy getting away, and nothing settled. One of those series left open for more but never happen or will probably never happen.
9. Final Fantasy Unlimited. Several cast members that sometimes more interesting then other cast member scarifice themselves to stop main villian. Afterwords you have no idea Ai, Yu, there parents, Lisa actually survive as you see them either dead or knocked out. You see there friends seemingly come to pick up them but there is nothing after that if they make it back to earth or they even are alive.
8. Burst Angel. Joe and Sei seemingly scarifice themselves to stop the bad guys. There are to many characters fate left open and Meg may or may not by the only survivor but she finds Jo's scarf tied up on a pole. Did Jo life after all? We never find out.
7. Gurren Lagann. Simon and Nia get married. Then Nia disappears/dies from defeating the spirals. Then see what seems to be a old man or older simon really looking like he has been alone all this time. Real sad and sucked man.
6. Revolutionary Girl Utena TV. Utena seems to die but you never see or confirmed her being dead. Anthy seems free and leaves school but before pretty much seems to think Utena is alive. There is no real conclusion to if she is or not. If she is sucks it is a bad ending.
5. Tokko. The show ends with Sakura scarifing herself so Ranmaru save the world. Then you Sakura in a comma like her brother before and it seems bad guy isn't dead after all. Sakura opens her eyes and it ends. There is no more to it. No more to the manga.
4. L/R. Great series with last episodes with more twist and turns that keep me wondering till it was over. Problem was it didn't end where should have. It ends with Rowe either shot or stabbed in the back by a coward out of nowhere and then Jack seems to be killed too. They don't show what happens. The last scene after credits seems to show them in their white car driving off saying where to next before going to white but are they dead? Who knows. It ends there.
3. Neon Genesis Evangelion TV and End Of EVA Move. Well obviously the FMA creators never watched Eva because they would have learned a lesson. TV show ends with a run of money two episodes that are confusing and are just bad. Then the movie spends most of the earlier part killing off a good part cast and then second half humanity. The movie ends with Shinji be given the fate humanity in apocalyptic world with Asuka. Then the movie ends with Asuka looking as hurt as rei was in episode 1 saying she hurts. That is how ends. Nough said.
2. Full Metal Alchemist First Series and Movie. How do you mess up ending twice? You end the TV show with Ed stuck in our world and then end the movie with Ed and Al stuck in our world in pre world war II Europe. As a matter of fact the last thing you see is a bad sign. Even though there is OVA that shows Al as old man but creator said that it may or may not count.
1. Gilgamesh. Where to begin. Show confusing plot ends with of the WTF moments in Anime history. Bad guys win and the world ends. Then a new humanity appears just to kill. Now that is wikiapedia says that was about. I'm lost on it.
Dragonball GT. It ends with Goku taking the Dragonballs afterworld and then we see Pan as a woman? Oy.
Steam Detectives. Is Ling-Ling and her sister seeing Narutaki who scarified himself to save the city or the butler or the villian Ling-Ling sister worked for? We never find out as we only see the legs of character and sisters reaction.
Dual. Much as I like Dual I wish there was more as last episode left open for so much more.
Ninja Scroll. Jubei survives final battle but doesn't tell Shigure that he is alive. She is left to think he is dead.
Gun X Sword. It ends Van and Wendy being reunited after years apart and wendy now older. We never find out what happens though got to love the reactions.
Area 88. Another unfinished ending.
Flag. Saeko is killed in last couple of minutes in a bomb attack on the airport on the way home.
Third Gatchamen series. Never seen it myself so I can't say if it's true but I heard in last series Gatchamen team dies in the end.
Black Cat. I'm not totally liking where everyone ends up apart at the end of the series. Great series.
Coyote Ragtime. Ending made the whole thing seem pointless.
Escaflowne. Hitomi and Van forever seperated by worlds. Sad really.
E's Otherwise. Does Kai come back or is he dead? Never revealed. Ends that way.
Excel Saga. It is Excel Saga style but the world drowned in blood?
Hellsing TV. It ends way to soon with Hellsing organtionzation being put in prison. Arcured is offers again Sir Hellsing to make her a vampire and it almost look like she actually considers it this time. It ends that way without a answer or what happens next. It just ends. Ultimate is a retalling more faithfull tell to manga.
Magic Knight Rayearth. Not a bad ending not totally a happy ending invain of Escaflowne ending.
Michel. After saving the island Michel sadly goes to sleep to get energy back. I hated this.
Pilot Candidate. Incomplete ending.
Ranma 1/2. Lots of stuff unsettled. Same with manga.
Utena Movie. As bad as the TV ending is at least Utena doesn't turn into a car and ends with her Anthy driving into the sunset with Utena being the car driving there. I read a manga version ending there was better then either TV or Movie ending.
Lain. Lain erases herself from the world? Huh?
FLCL. This was a confusing and not funny show. Seems like main character runs off with the girl at the end after she comes back but you never see what happens to them.
Utawarerumono. Another show that ends with lovers sperated seemingly forever.
Cowboy Bebop. Does spike die or live?
Samurai Champloo. Sorta sucks that all three just walk away with much of a word.
Romeo X Juliet. Sad ending just in vain of the original play but different then it from what I hear. I haven't watched it yet. Still sucks. Which they would have done something different.
Guyver, Bubblegum Crisis, Rave Master, Trinity Blood. Four more series that really end and nothing is resolved.
Eden's Bowy and This Ugly Yet Beautiful World. Lovers spearated probably forever.
Gantz, It ends with more questions then answers. Black ball disappears and seems the last survivor kills himself or does he?
First Ghost In The Shell Movie. Having to join with the villian and then stuck in a sucky cyborg body? That would not be a good ending.
Angel Links. Main character sad fate with no hope of changing it.
Petite Princess Yucie. Show ends seemingly still stuck Yucie as a kid and not growing. Though it looked like they tease that she did grow a little but again it's really left in the air.
Magikano. Almost feels like if Ground Hog's Day ended with Bill Murray still stuck in the loop. Really sucky that the characters are seem to be fated to stuck in this repeat.
Elfen Lied. Who is at the door?
Lost Universe. Is that Kain at the end or not? Man I hate that. All they could have done was shown in kain in ship or getting off instead of the insead the house.
Princess Tutu: She goes back to being a duck? That really sucked.