LOL! Some interestingly destructive ideas, there. Number 10 seems like the best way to go about it.
Strangely enough, though, I've seen this method proposed as a way to SAVE the Earth, from being eaten by the Sun as it expands into a red giant in another 5 billion years or so. Simply maneuver a sufficiently large asteroid into the proper orbit so that, once each year it will tug the Earth slightly further from the Sun.