Palpatine was evil. He first appeared in the Empire Strikes Back. He was portrayed by Clive Revill. But in Return Of The Jedi he was portrayed by Ian McDiarmid. McDiarmid was the better Palpatine. That's probably why he replaced Revill in the DVD version of The Empire Strikes Back.
Ian McDiarmid also portrayed Palpatine in Episodes I, II, and III. He was the only human character from the original films to star in the newer films. In Episodes I, II, and part of III, he wore no make-up.
The prophecy said that Anakin Skywalker would destroy the sith. The prophecy came true. Darth Vader destroyed the Sith(Palpatine and himself) in Return Of The Jedi.
I give Palpatine a 4 star rating.

Man, I hate it when they keep runnin' and backstabbin'... lot of those SITH LORDS play it both ways. It's the nature of the Dark Side of the Force, being unnatural. I never liked the guy. I always thought he was kinda creepy.

Love the lightning coming out of the fingers. But he had to die.

In my humble opinion, Emperor Palpatine is the most AWESOME villain to ever grace the movie screen. It's too bad that he was defeated by Vader. Why the hell did Vader have to go and do a stupid thing like going back to the side of good?

Evil, just pure evil with a capital E.

one mean SOB - he plays both ways, if you know what I mean...