Starz has been around since the mid-90s. It has some pretty good programming but it just doesn't get the attention that maybe HBO or Showtime does.
They had a really good short lived comedy series called "Party Down" that I loved. Had a great cast! https://m.imdb.com/title/tt1073507/
I think Outlander might be one of its more popular series now. Based on a book series and brought to TV by Ronald D Moore who did Battlestar Galactica (which personally I am cautious about because the last season or 2 of BSG was not my favorite)