Pandemic. There was a disease, but you survived? Sounds OK (at least compared to fighting zombies, aliens, or robots for the rest of your life).
But I choose Rapture. It proves a given religion, ending religious wars and laws. Takes away those who subscribed to that religion. Leaves the rest of us to get on with a non-religious but otherwise perfectly intact world. I don't have to hide from zombies or aliens or robots, no asteroid flattened my house, and there aren't millions of diseased corpses everywhere. Sounds good to me.