For me, it’d have to be Fleeting Words. It’s then a hard choice between the Weiss edition and Another Edit. I just really love it (and also that entire storyline).
Shadowlord, Exhausted 3, The Final Song, Song of the Ancients Devola, Wretched Weaponry Dynamic, The Tower, and Seere’s Prayer are also really great, and I think an underrated one is Cold Steel Coffin. Still waiting on an official piano Cold Steel Coffin…
For me, the original Nier I had on the 360 wasn’t a masterpiece, but boy did that music keep me engaged which is why I didn’t hesitate to pick up Automata.
Automata however was a 10/10 and they brought back some old favorites like Song of the Ancient’s and there was a version of Emil from an Arrangement album that is top tier. But Pascal’s Village and Amusement Park are my favorites from Automata.
Shameful plug - Friend A from Your Lie in April was also recommended on Spotify based on my Nier history. It scratched that itch so I was so confused when I went looking for where in the Nier series it was from and I got this random anime instead.
I’ll have to try listening to that track, I did hear good things about the show though. But good choices, Amusement Park is a classic.