This is a pretty interesting question, actually. Especially since so many of us were into trance during the late 90s era (and some even before), but have splintered off into other genres.
The stuff I'm gonna share below is definitely not most people's cup of tea, but is still arguably trance, and are memorable for better or worse:
And a bit older than some of the others I've shared (2007), but this is one of the last "classic" trance songs that I fell in love with:
