I thought the Emperor was pretty creepy, and it's still a great performance. He can be lazy like an old man cos he yields such great power, and his sardonic tone is fantastic IMO.

Palpatine on the other hand ... I liked the subtle manipulations, but, really, the Jedi came across as a bunch of bureaucrats unable to detect the single most darkest Sith right in their midst. I had hoped for a clever clone twist, but alas, all I got was "Qui Gonn taught me how to cheat death" and frickin midichlorians. And that stupid prophecy. I hate prophecies, but I do like the way Anakin restored balance to the force by chucking the Emperor down a handy shaft thus fulfilling the prophecy. I guess Plagueous never taught Palpatine levitation then ....