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).
The Whirling in Rags theme and Martinaise theme (the one with the distorted horn) from Disco Elysium.
Every boss theme from Metal Gear Rising: Revengeance.
About half of the character themes from Guilty Gear: Strive (and I haven't even played the game!).