If you could have an army of.....

[Circus Ascendant]

I direct anyone who wants an army of ninja here [http://tvtropes.org/pmwiki/pmwiki.php/Main/ConservationOfNinjutsu?from=Main.ConservationOfNinjitsu].

 

[Kingsman]

An army of those jellyfish Noise in The World Ends With You.

They'd just keep on self-replicating until they took over everything.

 

[LwaXley]

i'd want an army of rocks cause rocks rock man

 

[RootbeerJello]

An army of SoTC colossi. They wouldn't even need a battle plan, I'd just tell them to wander aimlessly near some buildings.

 

[ghostinthenight]

an army of idol rejects! the enemy would commit suicide just to escape the noise

 

[Tanfastic]

I'd have an army of mammoths. I dunno why, I think its the tusks.

 

[Guy32]

An army of $100 bills. Lots of them.

 

[Jurassic Rob]

An army of Zoidbergs! We would thrash all enemies with our never ending whooping!

 

[DXsiykiller]

an army of umpa lumpas

Need I say more?
Those things are just badass

 

[KeiraZodiac]

an army of mutants from the X-men comics, they would all have their own unique powers, so it would be awesome.

 

[Troublesome Lagomorph]

An army of Deathclaws with Tesla Cannons on their arms.

This. With robotic implants.

 

[letsnoobtehpwns]

Army of penguins!

 

[Fingolfin High-King of the Noldor]

An Army of Daleks. None would stand in my way.

An army of Time Lords! PWNED!

That already happened. And theres only 1 Timelord left.

 

[Pimppeter2]

Army of flies.

God, that would be so annoying

 

[DrScoobs]

an army of... metal gears!! they would kick ass

 

[S-Unleashed]

An army of ninja Kobolds.

 

[Unit Alpha]

An army of deities (or gods for those who don't know) would be pretty dang awesome.