I'll start off with Raiden II's Repeated Tragedy.
A local restaurant had this game, and every time we went, I'd beg my parents for money so that I could play it. I wasn't very good at the game, so I never got past the first stage, and so I heard this song a lot. Really gives me nostalgia.
Also got to shout out Streets, from Timesplitters too. I put a lot of time into this game as a kid, and this song is what got me into futurepop (love me some VNV Nation).
I have a soft spot for Half-life's soundtrack specifically:
Triage at Dawn
Something Secret Steers us
You're Not Supposed to be Here
Diabolical Adrenaline Guitar
Outside of Half-life:
BFG Division from DOOM (2016).
Sisters of Battle from Hollow Knight.
Gwyn Lord of Cinder from Dark Souls.
Majula theme from Dark Souls 2.
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