Ugly Casanova. Someone left modest mouse on the burner for too long and made a powdered concentrate.

Literally every album by The Mars Volta. Each one is unique and I'll never find anything like them again.

Yanni-live at the Acropolis. There's was a brief moment in 1994 when yanni actually achieved world peace. Also Tribute, another live album, that shows how unbelievably massive yanni was. He sold out a show at the fucking Taj Majal.

Anna ash and the family tree- hello friend, from bird above. An indie folk album that's a perfect cross between a prairie home companion and the hipster folk Renaissance of the early 2000s.

Pity sex-dark world. One of the best albums out there. Emo shoegaze garagy jams with killer guitar work.

Cocteau Twins: Heaven Or Las Vegas

My Bloody Valentine - Loveless
Nothing sounds quite like it

Extol's "Burial". Very smooth sounding record considering its bordering on Technical Death Metal.

Decapitated's "Nihility". I don't know if drums have ever sounded more violent, tonally.

Suffocation's "Pierced From Within". Unique in that IMO that level of brutality and density has still never been matched.

Ulver's "Nattens Madrigal". Bees in a tin can.

Literally anything by Ad Nauseum.

Man, I could go on and on about this. So many metal records have one of a kind production.

I've been trying to find something similar to Holly Herndon's Proto, but haven't succeeded yet.

https://www.youtube.com/playlist?list=PLWGJxgOf-Z3CW7tJoN9f4lzIf8CEuMgne

How is it possible that I'm the first to mention Days of Future Past?

Animal Collective

Loving and saving this whole thread, I'll add in

Ones & Zeros, Vol. 1 - 3rdegree, not SUPER unique, but it's instrumental and commitment to they're concept album's theme of uploading your consciousness into the internet gives it a ton of charm!

Larks' Tongues In Aspic - King Crimson , very surprised I haven't seen this one in the thread, a classic weird ass prog album by the Kings of Prog themselves (IMO of course). They got a guy to do a bunch of random sounds for the album and he left to become a monk days before they started the album tour lol.

This thread showed up like it was meant for me in this very moment as I'm currently laying in my sofa and blasting this on high volume and drowning in the vibe:

Afro Celt Sound System - Volume 2: Release (Real World Gold)

Haven't heard anything truly like it so I think it fits the thread.

This album has been with me since my childhood.
My mom used to house sit this crazy special house during the summers around 1998-2005 that belongs to a clay sculpture artist, my mom discovered this band there and loved this album especially.
It was mostly my mom, me (born 1990) and my little sister (born 1992) in the middle of the woods all summer break in this absolutely dream like house, it's something out of a movie really.
A lot of the house was built by the artist dude, with tons of handmade clay sculptures, mosaics, wooden details of animals and twisted tree logs built into the structure. The sides of the road through the woods to the house was filled with totem poles, human-ish figures and other sculptures.
We just enjoyed the woods and the house, made clay art and nice food, went bathing in the river and took care of the garden.
There are so many deeply connected smells, sounds, sights and feelings in me to that house, it really affected me in a great way.
I so wish I could post photos of it but I have no contact with the owner and don't want to do it without his permission.

Gustav holst - the planets

Makaveili - the don killuminati the 7 day theory

Madlib - beat konducta vol 5-6 in india

Scientist - rids the world of the evil curse of the vampires .

There are many more artists that come to mind with unique sounds but that have more than one album with that sound.

Neil Young, Le Noise is amazing on a good system. The sub sub octave acoustic efffect is very unique.

Protomen volume I - they purposely went against arbitrary recording "laws"

Rush-2112, moving pictures

Also a rare one: Burlap to Cashmere, ,is there anybody out there. Its soooo clearly mixed. Hard to find any in depth info on this album.

https://youtube.com/playlist?list=PLUfQzCvWRPGdjZQR2Snca0k275TIaJ8Qh

"In kommer Gösta" is my favourite proto-progg track!

possibly Speak for Yourself by Imogen Heap but I'm not sure

Natural Snow Buildings - The Dance of the Moon and the Sun. It's a mix of drone, post-rock, and folk that is unlike anything I've ever heard (NSB's other albums have similarities, but this one stands out to me)

Honorable mentions:

Boris - Flood

Agalloch - Ashes against the grain

Grace Cathedral Park - In the evenings of regret

Little Man by Little Dragon

Didn't see that accordion coming.

Fingathing and The Big Red Nebula Band by Fingathing. Kind of a big beat/instrumental hiphop thing, the band already has a fairly unique sound but it stands out even in their output.

One classic one I forgot

Art of noise - The seduction of claude debussy

Phenomenal blend of styles to create something truly unique.

Want to save this thread for later, may as well name a couple as well

The Faceless - Planetary Duality. Technical death metal album that found an outstanding balance between technically-impressive musicianship, interesting compositional intricacacies, and raw primal brutality. Nothing scratches that itch like this album does for me. And if you're into drums, Alex Rudinger's drumming in Xenochrist is wholly and entirely inhuman. The dude is an octopus trapped in a man's body. I'd recommend watching his Xenochrist drum playthrough video if you're particularly interested

Infected Mushroom - Converting Vegetarians. These two guys are absolute wizards of music production, and this album showcases their insane ability to bring out such colorful personalities from their meticulously crafted synth leads, through gradual and dramatic evolution... Which they usually do in a familiar psy-trance setting. But the "chill side" half of this album accomplishes this wonderfully in a unique, much more relaxed, low-tempo style that I'm genuinely struggling to find words to describe

One that comes to mind is Hella - Hold Your Horse Is

There have been 'Math Rock' bands before and since but these guys were on another level IMO, especially the drummer.

I would also say anything by Melt Banana.

Aleks and the Drummer — May a Lightning Bolt Caress You

It no longer seems to be easily streamable anywhere online, but it's an absolutely insane EP. You needs to listen to it either on good headphones or in surround sound, and that's a fraction of the live experience. When those thunderous drums roll in and the electric organ starts wailing... shivers.

Der Fall der Psychiatrie - Das Flug

At least that was the name I originally knew the EP as. I think it's since been rereleased as Alles Musz in Flammen Stehen

German electronic punk by a solo artist who's sadly stopped releasing music some time around 2015.

Steve Reich, music for 18 musicians

Gorguts - Obscura

Death metal band takes death metal and flips it on its head. I forget the exact phrasing from an interview with the frontman Luc Lemay, but he said they wanted to make their instruments speak in a new way. It's highly experimental and maybe tough to digest even for death metal fans, but it's undeniably unique and brilliant.

KLF - Chill Out

Astounding album. Nothing quite like it.

There are some greats listed here (Ween, Jarre, FSOL, Lovage, Aphex, Shpongle, Air, etc.)

However my pick is Mike Oldfield - Ommadawn The only thing similar to this is his own album Incantations a few years later, but there just isnt anything like it from start to finish.

LITERALLY EVERYTHING HORSE THE BAND HAS EVER DONE!

Seriously, one of the most under appreciated bands of all time. A Million Exploding Suns is a fucking masterpiece.

The Books - The Lemon of Pink