Star Wars used to be one of the top major factions in science fiction. A single Star Wars civilization could go toe to toe with a Warhammer 40K faction and at least engage them in a fight. With Disney making the EU non canon it seems that Star Wars suffered a huge nerf in terms of firepower for Star Wars. There are only a handful of science fiction settings that I believe Disney could win against. So far those are:
The Verse(Firefly)
Mass Effect
nBSG
Killzone
Modern Halo
Babylok 5 Younger Races(maybe)
What other science fiction factions could they win against and what is the strongest they could beat?