It all depends on the person ^^
For players of CoD and other "
reflex" games : xi - Ascension to Heaven (
https://osu.ppy.sh/s/34348)
For those "non-geeks", i tried to convert one with Touhou and Minecraft without success... But it works with osu !
Choose a music that can be loved by everyone (or almost) : Dubstep, rock, (metal),...
Lindsey Stirling - Crystallize
https://osu.ppy.sh/b/145458Or known musics :
Rick Astley - Never Gonna Give You Up -
https://osu.ppy.sh/s/977For geeks, I focus on nightcore musics, Vocaloid musics and possibly video games musics as Still Alive (Portal).