This opinion is based solely on a fan perspective, not a musically endowed one.
In my disgustingly humble opinion, I think Destiny 2: Witch Queen's Album is the best of Destiny's music. The story, the environment, the atmosphere, the gameplay (to some extent), and the raid (in a way) were at their best in this DLC — and what helped cement that was the music. I've gone back to listen to Destiny Music, and out of all the albums, I found the Witch Queen album to be the one where I rarely skipped a song. So many amazing and varied tracks: Queen's Deception, The Deserving, The Cunning, Insurrection, The First Disciple, Underworld, Hidden Truth, Lucent World, Dethroned, etc. Amazing piano numbers; the percussion was fiery on the Hive rave numbers like (The Lure, Lepidopterophobia, and the last half of The Cunning). And amazing solo vocal numbers that leave me weak (King's Descent and Yours to Win). This was the part of the story where everything we knew as Guardians was shrouded in Savathuun's lies and truths, and the story reflected this perfectly by having familiar leitmotifs distorted in fantastically strange ways.
The only albums that ever came close to matching the Witch Queen's consistent and versatile expertise were The Taken King and The Final Shape. Those two albums fell short only because of a lack of diversity. The Taken King had very dark, dirty orchestral pieces, Hive numbers, and heavy horns and drums (Regicide, Bow to No One, Cabal Breach, Enemy of my Enemy), which I loved, but I liked the album in parts, not as a whole. The Final Shape was pretty much the same. So many spectacular pieces (Ritual Site, Entropy, Unmade, A Knife in the Garden, Precipice, Stronger Together, Metacarpus, After All This Time). Again, blood-curdling action numbers and a fantastic orchestral piece that fits the end of the light and dark saga. But unlike The Taken King, almost every track was heavily orchestral; crystallised by a potpourri of leitmotifs that came and went with each song. This made sense. It was the final battle between an enemy that overshadowed all other dark factions. But the tracks were still a little too similar for me.
No hate intended and not expected. I love all the Destiny tracks; the composers are all amazing, and I'm so glad I get to live and listen to these masterpieces.