Pulverized by impact with blunt instrument
This option can be accomplished by sufficient impact with somewhat smaller objects, although it takes a lot of doing. However, consider one very large object in very convenient location: the Moon. Knocking the two together would make an excellent start. Moving the Moon into the Earth is somewhat easier than moving the whole Earth.
Hurled into the Sun
The sun's size can also be expanded to include Earth. Sunkiller bombs may be constructed in various ways to destabilize or artificially age stars, causing them to expire according to their class.
But it's all still comfortingly impossible with extant technology. I say comforting because humanity is currently destroying everything it can destroy and clearly should not be trusted with anything more.
I can see some poor supervillain working his way to the end of this list, having considered and discarded a vast array of options, and coming to the conclusion that Earth cannot in fact be destroyed ... he has a meltdown and is found bawling in a bar somewhere. Thereupon, someone calls Dr. G, because who else is going to counsel a mad scientist melting down over not being able to actually hurl the planet into the sun.