Avengers / Squadron Supreme '98

In 1998, Marvel launched this one-shot that pitted Earth's Mightiest Heroes against their morally ambiguous doppelgängers from a parallel world. Written by Kurt Busiek and Len Kaminski, with art by Carlos Pacheco, the issue explores the ideological clash between the Avengers and the Squadron Supreme, a team whose utopian methods blur the line between heroism and authoritarianism. A thoughtful, self-contained story from the late-'90s Marvel era, it stands as a compelling examination of justice and power dynamics within the superhero genre.