^
Couldn't the same argument be made for the Rebels or the Jedi for that matter?
Well, sure, it could be made about anyone seeking a position of authority. But for Bane and Palpatine, it was always about bringing the Sith to dominance.
One Sith I want to add to the noble Sith list is Lumiya. She pretty much sacrificed herself in order for Caedus to be born.
After she corrupted the son of Han and Leia Solo and convinced him to kill his fellow Jedi, murder his aunt, corrupt his cousin and dead brother's girlfriend, decide the galaxy would be better off if Han and Leia were dead, and take over the galaxy in a coup d'etat. Not to mention the numerous times she personally tried to kill Luke. Not really all that noble, is she?