In the early 90s, bjork, radiohead, portishead, massive attack and the tragically hip were awesome bands.
Shit started to get great at around 1998 though, with the montreal post-rock scene and DJ Shadow.
Collectively though, the vast majority of my music collection is from the last four years, peaking in 2005.
In fact, bjork, radiohead and the hip have all made their best work recently.
Anyway, I suppose it is all just a matter of personal taste. I grew up in the 90's, listening to grunge on the radio, my dad tried to be progressive and listen to new stuff, so I was constantly exposed to alternative. I stopped listening to music completley after about 1998, and then rediscovered rock altogether two years ago. Now I'm in a constant search for tunes I remember from my childhood. Every new find is a thrill, a buried treasure, a memory.
The order in which I rediscovered bands:
Pearl Jam
Soundgarden
Nirvana
Stone Temple Pilots
Bush
Radiohead
Alice in Chains
Third Eye Blind
Matchbox 20
Creed
Live
Cracker
Toadies
etc. etc. Every new band I rediscover expands my horizons greatly.