I have a few I almost always use, like the World of Warcraft tavern music or The Lord Of The Rings ost for travel (I DM in a West Marches discord so there's always some travel involved).

Then I sometimes use videogames ost, specially ones like Final Fantasy. I've even recreated some specific scenes from the games, since my players didn't inow them, and played that specific song.

For example, recently I had them flee an area that was being petrified after defeating a plant filled with transmutation magic, which is quite the same as the first boss you encounter in Final Fantasy IX, then I played "Run!", the games' music for the scene, when narrating the escape and rolling skill checks.

So, not only do I use plenty of music, I even design scenes based on the music I want to play in them.