These guys were once on top of the world. Then, Nirvana's Nevermind came along, and the fickle mainstream trend-hoppers turned their backs on hair metal. Excess, babes and good times were out; brooding was in. After grunge came the age of irony, when hair metal resurfaced as an amusing relic, but it was too late for most of its purveyors to regain their dignity. Oddly, only Jon Bon Jovi - who finishes up a four-show stint at the Air Canada Centre Monday (January 30) - has come through it all relatively unscathed, though the other guys get all the post-ironic hipster cred.