Thinking back to some games of yore I can no longer separate the game from the music I was obsessed with at the time. Is that the same for you???
Main ones for me are:
Skies of Arcadia (DC) - Origin of Symmetry (specifically Bliss and Hypermusic) - Had these on soulseek at the time, pre-release and rinsed these two on repeat for so so long
Final Fantasy 9 (PS1) - Soundgarden Superunknown - Specifically the bit where you emerge from the long tunnel and the world map opens up, pretty epic in its own right but with ALOONE IN THE SUPERUNKNOWNNN blasting out, lemme tells ya
Burnout 3 (PS2) - Jane's Addiction - Nothings shocking (specifically Ted, Just admit it) - Spent a week at uni with the same car on the same track trying to get as many takedowns as I could. Seemed to be that 'Ted...' was the chillingest song I could think of so it was on repeat. Worked too. 183 takedowns in one go.