Came here from OG.ru, playing DF since 33d. As someone would notice I'm russian - so watch out for bad grammar :)
None for now. But I'm thinking of possibilities.
MinePoint see here. Was abandoned (save deleted) due to a very high impact on my work productiveness :). Next forts will evolve much more slowly...
CatBane Fell to marksgoblins and stupidity.
Squashshoot. Suspended due to hude lag (4-5 FPS on average). Anyone with decent machine is welcome to continue, since I like it so much, it hurts to think, it'll never evolve further.
PagebendDwarven clear glass honeycomb. With lots of (not really)MegaProjects. I got tired of it after some time.
The Steel-Castle Of Fires Just as name says. Castle made entirely of Steel. With a lava moat. Abandoned due to excess epicness.
The Spiral of Stone Wanted to make giant spiraling tower. Ended up making a giant spiraling well. Was destroyed by a tantrum spiral after megabeast attack
Most successfull adventurer
He managed to knock a quest giant unconscious with a masterful throw of a troglodite hand. Then he chopped his lims off, and twisted his trusted sword in giant's chest, until it died. (Am I not nasty?)