I thought this was a lot of fun to read, but I'm kinda sick that way...

http://www.livescience.com/technology/10ways_destroyearth.html

So... Was I mentioned?

No. And my keep pouring acid on it until it melts to nothing idea didn't make it either.

A nuclear war should do it.

Nah, that would just scorch life from the surface. The article talks about basically erradicating the entire mass of the planet.

(1) Drill deep
(2) drop nucs
(3) ignite