The original “Mobile Suit Gundam” trilogy (79 up to ZZ), “SDF Macross” and “Macross: DYRL” come to mind. It only makes sense, since a good space opera requires epic soundtrack. And those are the really big ones. Evangelion also has a very nice opening theme.
The ones with Kevin Penkin on the OST. There’s at least two of them now (Made in Abyss, Tower of God), so I guess they’re not unique anymore, but hey
Shield Hero as well. And his music is definitely the highlight of that series.
Any anime with Kensuke Ushio as the composer, most notably Silent Voice and Liz and the Blue Bird with prepared piano. He also composed the soundtrack for Dandadan and Devil May Cry
Trigun and Cowboy Bebop for sure.
Cowboy Bebop and Samurai Champloo
Came here hoping to see Cowboy Bebop. Tank! is my ringtone, and i listen to Mushroom Hunting on a regular basis.
Girls Last Tour
impeccable vibes
Does the Macross plus Sharon Apple qualify?
This is the answer. One of the best anime soundtracks ever.
FLCL
Gurren Lagann has a lot of great music. Viral’s theme in particular is a banger.
maybe Jojo
(I watched only ~10ep.)
Clannad
I think most animes, which are based on visual novels, have unique soundtrack, so Steins;Gate maybe too.
Tom and JerryIt had full it’s soundtrack like in this video (I just have yuru yuri example)
Are there anime with full it’s soundtrack like in Tom & Jerry, i.e. where every action is music?
Devil man crybaby on Netflix. That soundtrack slaps
I still listen to Needless soundtrack to this day, it has a very virtuoso vibe with it’s guitar solos.
Ghost In The Shell: Stand Alone Complex
Also up there:
Macross Plus
Serial Experiments Lain
Teknuo no Escaflowne
Tenchi Muyo! RyoOhKi
Yes yes I am in fact old.
That’s a pretty difficult question without examples or some details on what you’re looking or.
Do song covers in non-music anime count as unique? Soundtrack for The Rolling Girls contains covers of The Blue Hearts (including Stones with a great Shamisen solo).
Girls Last Tour has Song of Raindrops as an ED to one of its episodes - it consists of vocals, soft beat and sounds of dropping water.
I am not sure what you define as unique soundtracks, but Bleach and Solo Leveling come to mind as possible answers for myself.