The Mad Season album was great too. I miss Layne Staley.
I've always felt Nirvana was terribly overrated. Of course, I listened to Nevermind and In Utero as much as anyone else when I was in high school (they're still great albums), but personally I would take Grohl's output with Foo Fighters over Nirvana.
Of all the grunge/alternative bands of that era, Soundgarden has always topped my list. I remember getting Louder Than Love after catching the Hands All Over video on MTV and feeling like I discovered something new. I went back to the record store within the week to get Ultramega OK, and this would have been in 1989, two years before Nevermind hit the stores.
I don't know if I ever listened to any more glam rock after that. I mean, there was a stretch there of about a month in 1990 which saw the release of Danzig II: Lucifuge, Alice In Chains' Facelift, and Jane's Addiction's Ritual De Lo Habitual. In fact, Facelift and Ritual were released on the same day, August 21, 1990, still a full year ahead of Nevermind.
The alternative explosion was going to happen whether Smells Like Teen Spirit had broke through or not. If it hadn't been Nirvana, it would have been somebody else, but the movement was already underway, and had been for over two years.