Are the Sith really Evil?

It's not really the "common good" if It's for the benefit of the strongest.

Can anyone here name a redeeming quality about Darth Sidious?

But the average Sith is the murderer. Powerful Sith are the ones who causes the death of hundreds of people. And the most powerful Sith are the ones who could be a potential threat to the entire galaxy.

Most Sith (not all) would do everything necessary to gain power. Now, here on earth people like that (Napoleon) wouldn't be called evil necessarily. But in fictional settings they are called evil.

The Empire he built would have whipped the Yuuzhan Vong, while the Republic he destroyed would have fallen to them.

True, he did have a force vision that the Yuuzhan Vong were coming, but I don't think he would have defended his empire to save the lives of others. He built his empire around himself, so being the emperor of course he would protect his own power. He wouldn't have easily given up his throne, and would have most likely sent waves upon waves of troops into a slaughter just to make sure he held his power.

With all their superweapons, the Empire probably would have defeated the Yuuzhan Vong, (Though since it never happened, I can't be sure) but it would have been more to selfishly hold power instead of save the galaxy. I wouldn't say him wanting to stay in total power so he can abuse and rule over the galaxy would be considered a redeeming quality.

This is exactly what I would say.
Morality is not based on good or bad, but the perspective you are viewing from.

Well, he was working for justice for his own people.
The Jedi wiped out his people.

His people were evil. All of them. And they started the wars with the Jedi. Every single time in history. Heck, seeing as the Sith Order were in hiding for the last 1000 years more sith were killed by other sith than by jedi. It's not really a sense of justice that motivates him, more like hatred and greed much as it did his predecessors.

I don't remember any moments him talking about avenging his fallen brothers, so if ya have any examples please share.

I always saw him wiping out the Jedi more of his way of eliminating any threats to his new empire, since the Jedi tend to mess up the Siths plans. I know he hated the Jedi just like any other Sith, but he never seemed like he killed them to bring justice. He still had the children killed, and sacraficed Dooku, his fellow Sith.

Ok, but we are not any different than the Sith.
We are greedy, and when we are very angry, we murder people.
So are we evil?