Hmmm, I never actually looked at this thread because of the title. But it's actually quite interesting.
One major song.....
Probably Queen - Bohemian Rhapsody
It's the first song I remember hearing from my Dad's vinal collection and it just amazed me and turned me to music.
Another would be Supertramp - Bloody Well Right
Because it was the first time I heard curse words and music. Revalational moment.