What makes an ending?

It Depends for me. I enjoy happy Endings, but not Generic ones. I like Sad Ending, But again not the Generic ones. I have only seen a few Anime with A good Ending lately like: Toradora, Gurren Lagann, and Eden of the East.
:}

It depends on the story, but for me a good ending has to have a couple of things.

A good ending has to finish the story, leave some room for imagination, and ensure that no bad spinoffs can be made.

I don't know what makes an ending, but I do know that I can't stand endings that doesn't have enough closure or impact. Leave too many things open for questioning and it'll feel as though the story isn't complete. And of course if the ending feels too cliche or rushed, then it'll ruin the overall mood which was built up to reach that particular moment. It's like finishing a house of cards and then sneezing on it at the last minute. Those type of endings are very frustrating.

The ending is only as good as the journey that leads up to it. I think many members have stated this opinion in more elaborate terms, but that's pretty much it.

My taste of what is an ending is the same as you are. I prefer it to be all happy for the main characters in the end. Nobody have to feel sadness (Sometimes, even for the villains if they exist), it's generally peaceful and the tears shown are happy tears. I just can't stand bad or sad ending.

Happy endings. Like in a romance anime, the two antagonists end up together -> and if we really want a good ending, spin forward the time to the marriage (Love Hina, for example, or Suzuka). However, I really hate sad endings. Fate/Stay Night might not be a sad ending, but it messed me up That's a big 'no-likey' for me, when finally the love turns out to be true, BOOM. And there always is no way for the dying/leaving character to be , leaving the other character lonely/with other characters. D'oh!
Or it can also be good in a Non-romance anime, if the storyline is about invasion, fighting, etc. that the protagonist SAVES the kingdom or W/E. In bad terms, that'd mean his death, and so sacrificing his life.

In short: I like happy endings, with no protagonist's death (nor of his/her friends).
I don't like sad endings. Death of the protagonist, his/her love, etc is messing me up for a time.

Oh, and not to mention just ENDING an anime is MESSING me up! Such a huge crime of ending a beautiful story! :[ i'm sure everyone feels like that, lol.

Personally, I like sad endings, dying of the main character, wasted effort, broken relationship, failed savior, etc. Endings that make me pissed, make me angry that I wanna break the damn table with my hand, made me sad for the whole day I could just lie on bed re-imagining the sadness that has been implied on me. An ending so sad I could curse the creator to rot in hell and burn till the end of time.

Yes I love that sad ending, Im not so such a fan of happy endings...I dont know why, but sad endings stir up something inside me which happy endings dont. If an anime or story reaches the end, and its a happy ending, I just go "Oh...so thats the end.", and I dont really feel much about it.

No shit. That ranks as one of the worst endings ever. At least on my list. I sat there for a little bit kinda bummed out. Horrible way to end it.

Anyway, really as long as there is adequate closure without fucking over the protagonist (Basically the same example as before) then it's fine.

Ending depends mostly on what anime series it is, genre, and plot. I really can't pinpoint a specific requirement for an ending to be good. I decide an ending if it's bad or good after watching the entire series from the start.