This series peaked with Maryann

It was all downhill from there. She was by far the best and most riveting villain in the series. So much fun to watch her cause havoc in Bon Temps and she was brilliantly portrayed by Forbes. She was also by far the most powerful villain in the series. The stuff that followed was underwhelming, the Authority, Warlow, Lilith, the witch, etc just couldn't reach the same level.