There are a lot of good songs, but today I will pick Megalovania by Toby Fox. https://youtu.be/KK3KXAECte4
I’m a fan of this banger myself
Easily Mythic Power from Pathfinder: Wrath of the Righteous. Especially in the context in-game the track is first dropped, it’s incredible.
Chemical Plant Zone, Sonic 2.
Cassette Beasts OST is amazing. “Wherever we are now” is probably my favorite.
Goldfinger & THPS
A lot of the old Apple II game sounds mainly due to just growing up playing on an Apple II. The Ultima series had some of the best music. Ultima III Ultima IV
‘Trial Of Thunder (5-3)’ from the ‘Crypt of the Necrodancer’ (Metal Soundtrack). I’m not a fan of this type of game and have never played it, but Familyjules totally shreds the original 8-bit soundtrack it had.
Alaska from SSX Tricky is cool
The speedy/daredevil comets in super mario galaxy
Riversong - Tonto’s Expanding Head Band (Universal Paperclip)
Danger from Secret of Mana / Seiken Densetsu 2. I love me some boss battle music!
Missing You - Kingdom Hearts II
Justin E Bell - All Gods from pillars of eternity
It has to one of these two for me, hard to pick: The Chersonese soundtrack from Outward or Fear Not This Night from Guild Wars 2.
The Outward one hits especially hard while adventuring through Chersonese!
Edit: typo