CIS

The CIS is an organization set up by the Sith in an attempt to topple the Galactic Republic. It eventually manages to achieve its goal, but at the cost of its entire fleet. The Republic was later re-established soon after.

The CIS employs droids as soldiers, which are (apparently) less effective than living organisms such as Daleks or Grunts. This is probably one of the reasons why the CIS had limited success in the Clone Wars.

The CIS were also unpopular, they were hated by everyone in the Galaxy except for those they conquered, which apparently love them for some reason. Even if a species who hates the CIS is conquered by them, they will suddenly love them for some reason.

This is unfortunate as, in reality, the CIS were not onyl just and fair but also effective. Their soldiers were far better than the crappy clones and they treated their conquered planets with respect. They always got a bad reputation though, and ended up joining SUCAS, which effectively ended their reign as a Galactic Superpower.