Hillary Clinton's emails that have produced to date no indication of any criminal or dangerous behavior on her part (other than having an improper private server) Donald Trump's refusal to release his tax returns, or George Bush's "loss" of millions emails including in the period leading up to the Iraq War. A Google search finds 349,000 news mentions of Trump's tax returns, but 4,890,000 mentions of Clinton's emails.
Bush-era email practices were far, far more worse. Newsweek reports:
Clinton’s email habits look positively transparent when compared with the subpoena-dodging, email-hiding, private-server-using George W. Bush administration. Between 2003 and 2009, the Bush White House “lost” 22 million emails. This correspondence included millions of emails written during the darkest period in America’s recent history, when the Bush administration was ginning up support for what turned out to be a disastrous war in Iraq with false claims that the country possessed weapons of mass destruction (WMD), and, later, when it was firing U.S. attorneys for political reasons.
Like Clinton, the Bush White House used a private email server— owned by the Republican National Committee. And the Bush administration failed to store its emails, as required by law, and then refused to comply with a congressional subpoena seeking some of those emails.