Two, I guess.
1) Classical: when I was a kid, I heard “1812 Overture” on the FM radio, and the tune, especially the cannon shots at the end – caught my attention. That turned me on to the versatility of classical music – and that it didn’t need words to be good and listenable.
Since then, I have enjoyed classical music of all types – everything from piano concerti to violin solos, to full symphonic works. I don’t like every piece, but I give composers a lot of respect for that they did.
More contemporary: I have always liked Leonard Cohen’s folk songs, but the one that gives me shivers every time is his song Suzanne – link: https://youtu.be/svitEEpI07E?feature=shared.
TO me, it’s a good tune, a bit of melancholy, a bit of optimism, a good narrative. Just a wonderful folk song.
Of course, others will have their own favorites, but these are mine.