Adam Kadmon's Evangelion Dark Fics are, IMO, very well-written (at least, the ones I've read) and for the most part aren't just Downer Endings, they're "reach through the monitor and belt you out of the chair" endings.
Hmmm... I can't think of any definitively Downer Ending fics by others I've read and liked, but this made me think about my own fan fictions. I write a lot of Dark Fic , but, strangely enough, I don't recall doing a lot in the ways of ending on the downnote.
The only fic of my own that I can think of that DEFINITELY had a Downer Ending is this one: https://www.fanfiction.net/s/7702539/1/Defeat - "Defeat" - a Legend of Zelda fanfic set in Skyward Sword, centering on Groose and a possible ending to one of the tedious Imprisoned-fights.
There also, now that I think of it this one: https://www.fanfiction.net/s/7779131/1/Behold-Thy-Hero - "Behold Thy Hero" - A Legend of Zelda / Ocarina of Time fic that deals with the "Hero is Defeated" timeline of the series and just... I don't think that fic is one of my best. I seriously went overboard on the darkness and made it obnoxiously grim-dark.
There's also "Road Trip" - my Super Smash Bros. Zombie Fic that has a Downer Ending as ONE of its Multiple Endings - but it probably doesn't count because it's a part of an ending-set and isn't the "canon" ending for the story, which I've decided is the happy ending / final ending.
In which I attempt to be a writer.
I know it sounds weird but hear me out.
While I do like happy endings and do not think Depressing stuff is DA BOMB, I really do like fics with Downer Endings, IF they are fitting to the plot and tone of the fic.
I especially loved 2 Regular Show Fics in particular, Asleep In A Blizzard and Rock Bottom.
Also, Im kind of Experiencing a backlash of supposedly "Earn Your Happy Ending" like Memoirs Of A Master And Diamonds that are bad In ways I cant elaborate at the moment.
I DO love Earn Your Happy Ending, A Different Lesson pulled it off amazingly and its not a bad trope by any means, though.
Discord: Waido X 255#1372 If you cant contact me on TV Tropes do it here.