Ok, I'll go first.
1980-something. I was attending an exclusive prep school, on full scholarship, and was completely unaware of what a good sound system could sound like. Unable to afford the transportation portion of the tuition, I dutifully pedaled my bike to school in all kinds of weather, frequently urged on by fellow students whizzing past me in their own Jeeps, Camaros, Trans-Ams, etc.
One day, a few hours prior to a school dance, I heard the opening drums & guitar to Tom Petty's "Refugee" coming from our theater room, which seated perhaps 150 people. It sounded more clean and powerful than anything I had ever heard in my life, including several live junior high bands, and I was drawn to its source like a moth to flame.
Enter Mike G--------. No one knew much about Mike. He wore a brown leather jacket, drove his own, perfectly restored '69 Camaro convertible, and was considerably rougher around the edges than anyone else in our class. He came from a town nobody had heard, coughed incessantly, and nobody messed with him.
Mike had brought what I have come to believe was a Pioneer SX-1980 to power that night's school dance, and hooked up to it were the largest speakers I had ever seen in my life. I believe they were Pioneers but beyond that I have no recall. The sound hit me in the chest, enveloped my entire being, and permeated my brain. I had no idea Tom Petty could sound this good, this loud, and I could not get enough. It was an instant addiction that has never truly left me.
The receiver looked impossibly complex to me; never before had I seen so many amazing silver dials, switches and levers. What did they all do? What if you pushed the wrong one? How could a mortal human being, let alone a man-child of Mike's provenance, possess such a glittering, fantastic machine erupting with power second only to Krakatoa? If it was a powerboat it would have been sending rooster tails of superheated water two hundred feet high; as it was, Mike was politely asked to turn his music down, lest he disturb the adjacent science wing any further. One poor soul dared peer into one of the shipping cartons strewn about the room and was promptly cuffed on the chin by Mike, with the remonstration "Don't touch my f**kin' stuff!" No one else looked into any boxes.
Oddly, I don't remember the music that night. Most likely I was distracted by Kara M-------, who had professed a deep, undeniable passion for me earlier that week but was somehow unavailable for even a fast dance. I was heartbroken, and although I later learned that her perennially golden skin was actually spray-on tan, no amount of powerful classic rock could raise me from my blue funk that night. Eventually, I got over Kara, but I have never outgrown good music played through a good system. It's not quite as exciting as kissing a girl, but it's damn close.