Born from the mess of a word that is "pwnage
". Pwnage meaning ownage, or overall dominance over poorer players in an online game, or simply something that is really cool. Pwnage can also be used to express that somethng is really cool.
e.g. "i just got given a PC for christmas!!"
However, the term "pwnage in a box" was created simply to say that something is really, really good! Or in gaming terms, that you have just really, really, owned someone.
e.g. "i just killed a lv 100 and didnt lose any hp :-)"
"dude.... that is pwnage in a box"