I really can't say which track first sparked my interest in electronic music, if you also take into account early 90s 'dance music'... I used to like stuff like N-Trance - Set You Free, etc (the days when I used to listen to the radio a LOT which I hardly ever do now)... but when I finished school, a couple of years later I went to a friend's birthday and she had stuff like the following playing:
Marmion - Schoenberg
http://www.youtube.com/watch?v=to9Q1YWY2wg
Drax II Ltd - Amphetamine
http://www.youtube.com/watch?v=DyGedwIjUwA
Legend B - Lost in Love
http://www.youtube.com/watch?v=27AXunGRo5E
Microbots - I Didn't Know What to Expect (couldn't find a decent link for this one sorry)
...she also was playing a whole heap of Carl Cox
That made me really curious to discover more of the underground sounds
Then around 1999 one of my friends at TAFE (college) had just come back from Amsterdam and had a heap of Euro trance... I asked for a listen and got into: Tiesto, Corsten, AVB, PVD, etc... and from that, I started to expand and listen to different genres...
I was REALLY curious to hear what Goa/Psy sounded like and I can remember one of the very first tunes I heard and LOVED was Hallucinogen - LSD...
http://www.youtube.com/watch?v=u7_HHN1HwT0