The show was groundbreaking. At this point in television history, shows were built mainly around single episodes. While there would occasionally be stories that would have a small arc, each episode would have some sort of a resolution. It was unheard of for a show to have a serialized story, with the thinking that audiences wouldn’t be able to pay attention to a story told over many episodes. Twin Peaks changed all that. Most importantly, Twin Peaks was one of the first shows that showcased just what could be done artistically on television. It proved that people were interested in more than just typical cop shows or shows about rich people fighting.
It was also legendary due to David Lynch being involved. Imagine if Quentin Tarantino had a show on Fox after he released Reservoir Dogs? It was unheard of for a director of Lynch’s stature to take part in a simple television show. Yet it allowed him to broaden his creative horizons by challenging himself. By attempting to create content he would be happy with while at the same time satisfying television standards and practices, he was able to explore some of the same wacky ideas he explored in movies like Blue Velvet while making a show that would play well in the sticks.