Hero System made its first appearance in 1981 as Champions, a RPG designed to recreate the world of four color comics. Since then, Hero Games has attempted to use the underlying mechanics for a wide variety of genres with varying degrees of success. It is currently in its sixth edition although our group uses 5th Edition revised instead.
I've use it with great success in a number of campaign settings. Most notably Shadowrun, our own version of the Marvel Universe and a Post-Apocalypse game combining Morrow Project, War of the Worlds and Gamma World. In fact, I use it for all my campaigns with the exception of fantasy.