Documented cases of empire run and supported slave trade (The wookies), torture of political prisoners (Han solo, Leia), Genocide and the destruction of an entire planet full of people to prove a point (Alderaan), the murder of people without due process (Luke's aunt and uncle, the failed commanders that Vader kills), extortion (the cloud city and Lando), consorting with criminal kingpins that run sex slaves, drugs, and murder people (The Hutts).
The dark side wasn't called the dark side for nothing. Those people were rotten. In real life they were roughly analogous to the Nazis. I believe they were even modeled after the Nazis. They were nothing but pure evil, folks. Their leader employed Jedi mind control techniques, and that's just wrong!
The Empire's chain of command goes like this:
The Random Officers
Everyone under Darth Vader on the list let the top two call the shots. Clones are totally submissive to command, and the Officers are going to choke if they don't behave. Now that we know that all the command is in Sidious's and Vader's hands, and that they alone are the evil characters, it is obvious that the entire empire a force for evil. Now, personally, I like Darth Vader. He's the best character in the entire series, but totally evil. Choking for a hobby? Not good on a resume. And Sidious... he shoots lightning from his hands, and aims it at poor Luke! Enough said.
I don't see a difference between them and the old republic other than that the old republic had a corrupt government that was worried more about border disputes than about slavery on tatooine . I don't really see anything that the empire actually did wrong until the Death Star. And even then that was to destroy the rebel alliance. The only reason the Jedi didn't like the empire was because it was run by sith. But they did the EXACT SAME THING that the republic was doing. There was still slavery in the outer rim, the hutts were still in business, etc. The clone wars and the galactic civil war were both USELESS! The whole fight was about Jedi vs sith. And even THATS stupid. I mean why when you get angry do you HAVE to turn to the dark side? When Luke was fighting Vader in the Death Star he got angry and actually WON the battle. But when he didn't be got his hand cut off! I mean why can't you just have anger but not be a huge baby like Anakin? Ok I've gotten a little off topic now.
Vader had an excuse. What happened to him was unrepairable. He lost his mother and his girlfriend. To me there really almost was no bad people in "Star Wars." The only one that was bad was Paladaine as he twisted Anakin's mind. I think he was just as good as the others. So much so, that in the end of the Episode 6, a hologram acting as ghosts shows Anakin alongside Obi-Wan.
Proof: Darth Vader was played by a black man, it sounds very much to me like a case of rebel racism. Further proof: the "rebels" were examples of the same rebellious and unruly spirit as the Confederates had, and they were the original racists. Also George A. Lucas was married to a black woman so draw your own conclusions.
While the fact that the Republic was a decadent rule does not necessarily implicate the Empire was good, it at least proves that the Empire (at worst) was equally bad to the Republic and not actually worse. Hence in this aspect neither of them was "good" and neither was "evil". The Republic was an extremely bureaucratic rule that only cared about the interests of the powerful and wealthy like most political regimes that have existed. They did not care about the welfare of the Outer Rim (i.E. Tatooine and non-Republic planets could be ridden by outlaws, crime syndicates, and slave trade). Republic planets often treated non-humans as crap, i.e. in Naboo the Gungans were treated as inferior to the humans and only when they requested their assistance would they treat them as "supposed equals" (mostly TO USE THEM as cannon fodder). Corusant was ridden with corrupt politicians who only cared about their own welfare and they favored the Jedi Order which is arguably good, because Jedis are oppressive enough in their religious faith to obliterate anyone who thinks different. They would expel and declare as enemies anyone who was against the light side of the force. It is known that any powerful and truly good Jedi would understand BOTH sides and contemplate on them both and not be dogmatically bound to a single side. The Jedis PURPOSELY withheld information from members of the Order and told them that any knowledge of the "Dark Side" was plain evil, any Jedi who is willing to understand the Dark Side is immediately banned and treated as evil. Historically you know who else is so dogmatically narrow-minded and fanatical: people like Nazis, the Roman Catholic Vatican, and Al Qaeda.
In the popular science fiction film "Star Wars", the Empire was not truly evil because in the end Darth Vader kills the Emperor. He has a change of heart because of his son, Luke Skywalker. In the end, human emption conquers the evil of the Empire. It was not all that evil to begin with.
The sith might rule the empire, but the people in the empire are just obeying rules the sith give them or else they will die. Would you give your life or follow rules. They would find the republic destroy them and rule everybody if they were evil, but they were smart all the empire wanted was a little power
If we take a look at history today we can see that (almost) every empire tried to prevent rebellions in the country. Like for example (I know I'm going to get a lot of hate for this) the British empire tried to defeat the rebels in today's USA. In my opinion they are not evil.
Without the rebellion look at the empire, its just a system how the galaxy lives. The only reason they blew up alderaan is because they were protecting them selves. Its no different from the republic. Look at jabba his business is still untouched and slavery is still in there. So think of the empire without the rebellion.
Everyone tries to say that the Empire was evil, but what proof do you have to that argument? Luke was completely unaffected by the Empire's existence, and yet suddenly changes his religion and his world views after an hour of talking to Obi Wan? Indeed, throughout the entire series, you never once see oppression in the empire. The only "evil" thing they do is destroy Alderaan, which was aiding and abetting the rebellion which killed many innocents. At the same time, The rebels killed millions. The jedi were the true cancers to the universe.
I think that it is one of cinema's greatest flaws to think that the empire in Star Wars was evil. It was always implied that they were a bad group of people, but it was never actually shown or explained why exactly one should consider them to be an unsavory clan.