At a game design technicalities level, it handles a wide range of power levels well, in many types of setting. It notably does a good job with ordinary people, real-world knowledge, technology and weaponry, and with the recent past through to the near future. It stands up well to being extended without suffering severe "power creep".
As examples, I've run three campaigns in it which it handled well, and which I don't think would have worked nearly as well in other systems.
Steam! was a steampunk game that entered a technological runaway in the 1890s, and was aiming for a singularity by 1940. It will never be completed now, because one of the core players became unable to continue, but it featured enemies with time travel, who succumbed to
Moravec's version of Niven's law of time travel, a Martian invasion that was essentially a sociological problem, variant laws of physics worked out in enough detail to make nuclear weapons impossible and reactors easy, and minds uploaded into Babbage machines.
Laundry was set in the world of Charles Stross'
Laundry stories, and featured plotlines arising from the implications of
P=NP, the true purpose of Stonehenge having been a mystery for most of the last 5000 years, and the Laundry's semiotics department.
Infinite Cabal uses the Infinite Worlds setting, with rather loose adherence to canon, and rational Cabalists as the PCs, charged by the Grand Master of their Lodge (Isaac Newton, and the Royal Society) with finding out how the universe really works. They've learned one anthropomorphic answer so far, and are working on a physics-based one. This Wednesday evening, they may discover where echoes of Homeline come from.
GURPS lets me run this kind of stuff and doesn't fight back. Hero System is too based in superhero tropes for me to be happy with it, BRP/CoC doesn't handle the power levels and lacks the technological and magical support material, and FATE is too much about story action points.