Sam Hughes maintains a detailed analysis of what it would take to destroy the Earth. Needless to say it’s a lot harder than most sci-fi movies make it look.

His mission statement for the analysis is:

For the purposes of what I hope to be a technically and scientifically accurate document, I will define our goal thus: by any means necessary, to render the Earth into a form in which it may no longer be considered a planet. Such forms include, but are most definitely not limited to: two or more planets; any number of smaller asteroids; a quantum singularity; a dust cloud.