DarthIsildur

Palpatine aka Sidious was hands down the most powerful. Anyone who voted for vader has to concede to that fact because why else would he have served Sidious? As for being good with a lightsabre... its never even shown in the movies that he handles 1, but he could obviously beat vader and Dooku (implied by the fact that they both bowed down to him, just look at how anikan acts toward obi-wan... if his own master has a hard time controling him then why else would he so quickly and easliy bow down to Sidious?) And as for "raw power" how much do you think it would take to fool the entire jedi council right under their noses, while they pry into his (supposed) home planet of naboo and rising the ranks of the galactic senate. and as far as the "weakness of the lightning"... please, he was a sadist just like any other sith, he wanted to see the 1 who defied him suffer as long as possible, in fact if anything it shows more power that he kept luke alive long enough to have vader save him. in conclusion its obvious that Sidious was the most powerful Sith Lord