Here we find the perfect site for those of you wanting to annihilate an Earth-like planet. And, incidentally, it contains some good info that can be applied to sci-fi planet-killers.
The introductory paragraphs alone are worth the click. Give them a read and ponder just how utterly pissed off the Xindi must've been. After all, they weren't even bothering to go up against humanity . . . they were utterly destroying every planet upon which humans existed.
(Speaking of the Xindi, there has been some confusion as to what to call their planet-killing weapon. It was generally (if unimaginatively) referred to as "the Xindi weapon" in Enterprise. "Xindi Death Star" seems to have become the most common fan name.
In any case, the above gives me a topical excuse to link to the Lost Hope trailer/spoof site, where we can find alternate names for the Xindi weapon. Give it a view. )