You have a giant laser...

[Aerodynamic]

Canada, France, and Japan.

no reason I picked these, I just want to test it out.

 

[holographicman]

i would wait until all the world leaders got together at the next big UN meeting, then fire it to total anarchy

 

[annoyinglizardvoice]

I'd probably keep it until the next time I see someone who something really stupid/selfish.
Either that or zap some of the most dodgy, bigoted religious folks I can think of and try and claim it was an act of God

 

[DanDeFool]

I would fire it straight up the vagina of the woman who will give birth to the anti-Christ, at just enough power to give her the world's fastest hysterectomy.

Sorry babe. Blameless innocent though you may be, I'm too much of a pragmatist and too much of an asshole to let El Diablo have his way. If somebody has to be a dick to save the world, it might as well be me.

EDIT: Alternate target, assuming Biblical apocalypse scenario is bollocks: Michael Bay, at his luncheon with George Lucas and Hayden Christensen discussing another Star Wars spin-off movie.

 

[dashiz94]

I'd pile every single big corporate manipulating bastards, corrupt as all hell political leaders, and every terrorist leader into one room and fire it at that. Then maybe throw some poo at the rubble

 

[Taddy]

I'd fire it at the Prime Minister of Australia. Really don't like her or trust her.

 

[Magnalian]

If it can fire on anything in the world, can I make it fire at itself? I'd love to see a laser do that!

 

[Booze Zombie]

I don't fire it, instead, I steal it, figure out how it works and make it so I can knock stuff out of space and steal da precious metal.

 

[Kl4pp5tuhl]

Michael. Bay.

(He would have wanted to die that way, I think.)

 

[TheYellowCellPhone]

The moon. Que the destruction of Earth and the most entertaining video on YouTube.

 

[satanic kitty]

fire it at Pluto.... god i hate that place.

 

[Hashime]

I would fire it into a fusion reaction chamber and power the world.

 

[open trap]

well first i would hold a convention for all disney channel stars and teen idols, and then shoot it there, get Beiber, gaga, jonas, and miley sirus all in one shot.

 

[FetaFrosch]

i would build a gaint head, with big eyes, and i would fire the lazer right through it's mouth!

Spoiler

Damn ninja'd

 

[hottsaucekid]

Gabe Newell.
simply because portal was too short.

 

[greenflash]

i fire it at a time space rift so it gos back in time and destroys facebook games. and then buy(steal) a massive battery and recarge it and CUT OPEN THE FABRIC OF ALL TIME AND SPACE!

 

[SD-Fiend]

the kid that stole my GBA SP