Hotline Miami is a near perfect game.
I assume it's already been mentioned, so I'm not going to list music from the soundtrack of Baldur's Gate II, which sticks to me more than any other game.
One that I can't explain is the soundtrack of Heroes IV- especially the Chaos and Nature themes. So many memories of late night escapades with friends, I guess. In the same way we used to play RISK games that lasted a week, we played Heroes IV games that lasted awhile.
[youtube]https://youtu.be/mA7A5MbGy4M[/youtube]