There were none. Please watch the movies again. And then again. And one more time to get it into your head. What was "Sith" in the PT was not in the OT. After that, even if you take into account what was exposed in the PT, would only still possibly leave Palpatine, as Anakin was most definitely not.
I'm Going to have to disagree about that....
If we are leaving race out of it, because after Disney gutted the EU im not sure if the actual Sith race exists or not anymore, and we are going by a pure apples to oranges comparison... Sith is to Jedi style... Darth Vader was absolutely a sith lord and doing sith philosophy. Arguably as soon as he assisted unwittingly in Master Windu's possible (i still have hope) demise...
ill even go into further argument towards the fact he was in the OT, due to the fact that the return of "jedi" could not have happened. Luke was never properly or even lengthily trained to be a Jedi in the first place (he would have been the youngling who never graduated) ... so it was really the return of the republic...and more so if it was in fact the return of the Jedi as the movie would have you believe. And Force Ghosts only can do so much....
Ani has years and years of sith training's and IMO is absolutely sith by the time we are once again (first?) introduced to him... in fact his redeeming move of killing Palps is even completing/ending the sith circle of apprentice killing master.
i know my point/argument isnt as well written as i wish, but i think the point comes across....
also the sith rule of two was, by again movie and clone wars standards , more in effect during the OT with palp and vader, then it was in the PT-CW-OT start... because we had Dooku, ventress, Savage ect.... some more "sith" then others but certainly no less then Vader....
Im sure you have your own logic behind your reasoning, but i healthily disagree and raise you a question as to your thinking....