Lord Lucien
Lets all love Lain
You got Lumiya, Carnor Jax, Reborn Palpatine, Disciples of Ragnos, Caedus, The Lost Tribe (all within 40 years). And during and after that you have the One Sith. In less than two centuries you get all these individuals and groups with the Sith titles.
Before that you have the Ancient Sith, Sith Empire-in-Exile, Sorcerers of Tund, Freedon Nadd, the Naddists, the Krath, Brotherhood of the Sith, Revan and Malak, Sith Triumvirate, Brotherhood of Darkness, Mecrosa, Dark Force, and finally the Rule of Two.
Jebus...