What I appreciate the most from the 'grunge' era was the stripped down 'back to basics' nature of the music and where it steered mainstream music as a whole.
Not a bunch of effects and "new fad" digital sounds. Not a bunch of hair, make-up, and ridiculous costumes. It was guitars, drums, bass, and vocals...what a concept. The recordings actually sounded like something you'd hear live.
It was the counter-culture to the 80's...which had become all about the image and technology, and not the music itself.
So while I wasn't always crazy about every big grunge band, I respect how that era swung the pendulum.
Heck, I remember reading about how Nirvana and Pearl Jam thought their debut albums were "over-produced". Pearl Jam actually re-released Ten not long ago, and they took out all the hazy reverb and turned the guitars up...it sounds amazing compared to the original (which was still good obviously).
I feel like we're in the middle of another "80's-like" era right now...with a lot of carbon copied music across most genre's that's more about the image/tech than the songs and music. I wonder if something will come along at some point that swings it back the other way again.