EDIT: Seems dynamic music is back in style in some very recent games, many of which I haven't really played yet. Good. 
For me, it's dynamic music, the kind that some games had that adjusted moment by moment to what was happening in the game.
The best-known example of this in the 90s game TIE Fighter, where the moment more enemy (or allied) ships showed up the music would have a little additional flourish to acknowledge the shift in battle. There were pre-battle tension tracks, battle music, complications of battle, grandiose flourishes for the arrival of enemy or even allied capital ships, and victory and failure music all ready to flow into the next seconds of the game.
A lesser-known but still excellent example of this was in Ultima Underworld and its sequel, where drawing a weapon had its own special "preparing for battle" tension music, getting attacked had a jump-out-of-your-skin joltingly sudden musical start that actually scared me as a kid when I got ambushed, music for battles going well, going poorly, victory and defeat.
I wish more games did those sort of second by second musical changes, but they've sort of fallen out of fashion for the most part. 
The arcade experience. I remember that feeling of walking into a new arcade and just spending hours discovering shit. Walking down the line and seeing some faves, then seeing some crazy machine you've never seen and popping in a quarter ands hooting bad guys together with a wisecracking rando.
Arcades also let you readily and cheaply engage with physical mechanics. You might crawl onto a motorbike and physically tilt your body to steer, dance like a nut until you were sweating and panting, or crawl INSIDE of a jeep and shoot dinosaurs with a mate while velociraptors roar behind you.in surround sound