I think in many ways, network TV has never seen anything like Twin Peaks. Whenever I hear someone talking about it, I'm still amazed that this drama was on network TV!
It was so innovative and radical, with a cryptic plot, bizarre character, and a completely non-standard narrative.
Many of the shows that weren't directed by Lynch were somewhat sub-par, and I think the show went downhill after they revealed Laura Palmer's killer, but I can't think of any other show that had me waiting week to week like that. The freaking network also hurt it by moving it to a late slot on Saturday night.
I saw Fire Walk with Me- I enjoyed it partly, but it doesn't stand up against the series.