Anime fans on SG - What's your favorite anime soundtrack?

It's been a long time since I watched an anime. Here are some songs that I remember fondly:

Boogiepop Phantom (ending): https://www.youtube.com/watch?v=KHIx9Ksz9uI
Rurouni Kenshin 1/3 no Junjou na Kanjou: https://www.youtube.com/watch?v=rzziisIJudY
MACROSS 7 - Totsugeki Love Heart: https://www.youtube.com/watch?v=eWNZK_BIqVU
Yu Yu Hakusho - Anbaransu Na Kiss o Shite: https://www.youtube.com/watch?v=TL_T3ucVMzY
Gakkō no Kaidan ending: https://www.youtube.com/watch?v=cBPYy3AC76k
Hokuto No Ken - You wa Shock: https://www.youtube.com/watch?v=RxkezvGwI20
Vandread - Ending: https://www.youtube.com/watch?v=r3okO3oMV54
Blue Submarine 6 ending: https://www.youtube.com/watch?v=8NYKMzG8yys

Not exactly a soundtrack (I think?). but the whole FLCL series is full of bangers

I watch old anime, stuff like Akira, Vampire Hunter D, Street Fighter, Fatal Fury, Lupin, Riding Bean, DBZ, Ranma 1/2. Most newer anime's don't resonate with me, though I did like Appleseed, never saw the original from the 80's. Also like the Castlevania anime on Netflix.

Edit: And I'm an idiot, because I only now realized this thread was about soundtracks, lawl. Can't say I have a favorite, but it's nice when the music fits the ambience of the scene.

Kaiba
Clannad
GTO

How in the hell has no one mentioned Violet Evergarden yet?
Everything about this anime was beautiful, but the music, man... I love it.

Im not so much into Soundtracks or generally a big music listener. But one Soundtrack i always cna remember is Rage your Dream from Initial D.

Nodame Cantabile, and the trilogy of Cowboy Bebop, Samurai Champloo, and Kids on the Slope all have unique musical gimmicks that's expressed wonderfully in their soundtracks.

My number one OST in the medium has to be the one to Ping Pong, though. I love all Yuasa's shows and their soundtracks, but Ping Pong's stands out for managing to make table tennis matches fist-pumpingly exciting to someone who otherwise only gets into sports if they involve people punching, kicking, pushing, and/or trying to tear each other's arms off: https://www.youtube.com/watch?v=62qWI7CpIds

Taku Iwasaki's works. He's sooo talented, capable of working in multiple genres. Jormungand, TTGL, Noragami, Akame ga Kill, JoJo, Bungou Stray Dogs and Soul Eater are just prime examples.

There are tons of anime OST that I would call great, each for a different reason. Its nice to search for soundtracks of unknown/unwatched anime too, as many gems can be uncovered in the process.
My favourites are too many to list in a reasonable fashion, and many of them were already mentioned. So I try to drop some unmentioned/less popular titles into the lot.
I hope you dont mind mentioning OP/ED too, as I belive these are also part of the overall soundtracks.

Seikon no Qwaser - the whole OST is just so nice; the contrast between the music and the actual anime baffles me! Most OP/ED are bangers too!
Needless - OP Quite a rocking OP. Otherwise could have been a great fighting story, but its ecchi and crossdressign-fetish ruined it for me.
Shakugan no Shana - I would recommend the full OST, all OP/ED included, but to provide some stuff, THIS THIS andTHIS
Inuyashiki OP - Man, I realize how my recommandations may bend towards rock sometimes. xD Excuse me, while I listen to many genre, broadly speaking rock is my favourite.
Fate/Zero OST - If something is EPIC with caitals...this OST is it!
Bleach - On the Precipice of Defeat - I know, not the most popular among the other Bleach tracks, maybe not even among the best, but I just love the eerie, otherworldy atmosphere with the underlying urgency it delivers. Its quite unique IMO. EDIT: forgot to link this one.
Soul Eater - Whole OST is just something else. OP/ED included. Was a good anime overall. Wish they'd redo the ending FMA Brotherhood style.
Casshern Sins - Aoi Kage
Lastly some music that also comes to mind: Shikabane Hime OP, Ergo Proxy OP, Code Geass [OST]; Stories and Picaresque in particular, To Aru Majutsu no Index - Jellyfish, Suzumiya Haruhi no Yuutsu - God knows and so much more, but I will spare You. :D

If you dont mind instrumental music, and are not affraid to go down the rabbit hole (and its deeper than you can imagine), go discover Touhou and its music! But be warned! Once you submerge into fan music territory, there is no going back! You will be lost forever. I know I am. But I enjoy every second of it. :)

Evangelion's soundtrack is just flat out amazing, and the way it was incorporated into Shin Godzilla was like hearing it for the first time again. Simply amazing work.

I used to watch anime as a child so my favorites might be not as popular as other animes/soundtracks.

Inuyasha:
https://www.youtube.com/playlist?list=PLsonvEG2DW3NpMmTQvDwZ-vtVdErFmrXF

Ergo Proxy:
https://www.youtube.com/watch?v=nYtteOe9iBw

Here's some of my favorites. I haven't watched any anime for years, but still listen to these regularly.
Serial Experiments Lain
Zankyou no Terror
Baccano!
Durarara!!
Kurenai
FLCL
Claymore