Woah, there's a thread for this show here?
Amazing!
I think the show began to go downhill when they broke up the Dale Cooper/Audrey Horne relationship.
They had the hottest chemistry on the show, and I heard that it was Kyle MacLachlan who insisted that they end that storyline because he felt in inappropriate for Agent Cooper to become involved with a high school student. Kyle was a fool for not knowing what the show had with Dale/Audrey, and pairing them up in zero-chemistry couplings - Dale/Annie, John/Audrey - killed the show.
Ironically, Annie was no more appropriate for Dale than Audrey was, as she was about the same age, and Heather Graham was actually younger than Sherilyn Fenn. And Billy Zane's character, John, was about the same age as Agent Cooper, so what was the point?
The producers should've just kept it Dale/Audrey and told Kyle to deal with it.