Green Day have ruled the world twice, once during the landscape-altering success of Dookie, and again upon their American Idiot return from hiatus. Since then, however, they've struggled to recapture such heights. 21st Century Breakdown kept them in the public eye to a degree, but a slow decline has forced many fans to admit that they're not quite the globe-conquering force they once were. They still remain one of the biggest bands on the planet, as their recent induction into the Rock & Roll Hall of Fame demonstrates, but aren't exactly front and centre in the public's musical consciousness anymore.