Really depends on the genre of 90's alternative music. God what a great decade, never ever again will we experience one like it. It wasn't just music either it was really an all encompassing experience. Entertainment really peaked or at least for the time and we were just bombarded with all these awesome options and here's the kicker - RADIO WAS STILL RELEVANT
As far as the harder stuff obviously you got Nirvana, Tool, RATM, Silverchair, Soundgarden, Stone Temple Pilots, Bush, Rob Zombie, The Offspring, Green Day, I could go on....
It wasn't all about the hard stuff though there was a niche in the 90's scene where all these guys fit in (I REALLY loved this kind of music btw) - Oasis, Beck, Jamiroqui, Savage Garden wasn't bad, Third Eye Blind I still love, RHCP, 311, NIN, Live, Better Than Ezra, Hole, hell No Doubt was even good, Cranberries, Cake, Lit, Len, Verve Pipe, Blues Traveler, Everclear, Everlast, Presidents of the United States of America....If there is a heaven mine would be a continuous never ending loop of the 90's as a whole.
Even after the 90's these guys started to come out - A Perfect Circle, Disturbed, Drowning Pool, Powerman 5000, Staind, Slipknot, SOAD, Incubus, Prodigy, Orgy, Static X, KoRn, Limp Bizkit was badass in their time, Blink 182 before they sold out, Eve 6 wasn't bad, you get the idea though music was GOOD!