Was it from long ago, or something more recent? What made it memorable?
This might be a tough question for a lot of people: defining what good sound is, and separating sound from music isn't easy. It might be impossible to distill it to just one album or song. We tend to like the sound of music we like, and conflate good sound with good music. That's understandable, but when the sound jumps out and draws your attention, take, for example, the sound of Jimi Hendrix's feedback. It was Hendrix's distortion, not his songs, that forever changed the sound of electric guitars.
Paul McCartney said it was the sound of the Beach Boys' "Pet Sounds" album that inspired the Beatles to radically change their sound and make "Sgt. Pepper's Lonely Hearts Club Band."
For me, it was the first Led Zeppelin album. The music hit me hard, of course, but it really was the power of the recording; everything else sounded like black-and-white, and Zeppelin's music was in Technicolor. Bonham's drums in particular were so much bigger, more immediate and driving than other records in the late 1960s. Motown and the Beatles records were way up there for me, but Zeppelin's sound was beyond the rest. I wanted to hear that sound more clearly, and that's how I became an audiophile.
The first and second Zeppelin records were always with me when I was shopping for new hi-fi gear. The methodology was pretty straightforward; the speaker or amp had to unleash more of what was in the grooves, and the more exciting the sound was, the happier I was. I'd crank the volume way up and wait for something to happen. When a speaker or amp did the trick, I bought it. In the late 1970s, it was Brian Eno's "Here Come the Warm Jets" (what a great title), "Another Green World," and "Before and After Science." Eno's soundscapes and use of space really fired my imagination. The sound was at once abstract and emotionally charged.
I recently asked Stereophile magazine's editor, John Atkinson, to name the record that made him take notice of the sound, and without hesitating for a second he said, "Jimi Hendrix, 'Electric Ladyland.'" Good choice!
What about you? I want to hear how it hit you; was it on the radio, at a friend's house, or did you just buy something you read about?