15,000 knights are charging at you in full plate mail and all you're armed with is...

[Hanzo Hattori]

Admin gun. I win.

 

[Angerwing]

Force lightning motherfuckers.

 

[Knight of Cydonia]

The arbiter....anyone here played halo wars?
OR 15000 slightly BETTER knights

 

[Latinidiot]

the Clementine.

ROCK ON!!

 

[Lonely Swordsman]

Probably whatever weapon they're carrying (lance or sword)
Might as well go out in style.

 

[I_LIKE_CAKE]

Call in an A-10 Warthog to strafe that line they helpfully made.

 

[Twistshock]

Hadouken.

 

[Klarinette]

Er, I probably wouldn't be armed with much more than a purse or pocket knife, especially if I happened to be strolling down the street or something when they came at me. I'd be screwed.

 

[Aunel]

the ace of spades.
the only card I need.

 

[SilentVirus]

Spartan-2s'...And lots of 'em.

 

[Marowit]

a tank from one of the CoD games. that's a weapon right?

Just lock the door tight and run over anyone who you can't shoot.

 

[ryai458]

the wunderwaffe from COD world at war one shot jumps from the knights and kills them all mwhahahahaha!!

 

[experiment0789]

Hate to ruin the stream of creative answers, but, why not just shoot them? Armor isn't bullet proof or even bullet resistant. Hell, arrows went through the suits.
Maybe a nice fixed gun, like a mounted 50.cal or an M60, with a rather large barrel to finish them all off.

That's why there is 15,000 of them!

oh nothing special just a fully armored battlesuit

Spoiler

ah yes this should suffice

Well....it's still a good idea.think of it this way,a Meac/zoide/fully armored battlesuit can carry more then one weapon.
Since the post question was
"What weapon from a recent videogame would you use to defend yourself?"

Freakout456 just found a loop-hole in the question!

Good job,I was going to say force power from the force unleashed, but I like your idea better(I'm not going to take it)!
You do still need alot of ammo.

 

[LordWalter]

The Team Fortress 2 Engineer's Sentry Gun. Several of them preferably.

 

[AndyFromMonday]

I'll just -Nuclear launch detected- their ass.

 

[StarStruckStrumpets]

I am the only one who is thinking that an army coming after me is a horrifying prospect?

Anyway, I'd probably use Yamato. Dice them up good.

 

[OddOzZy666]

The ray sphere. Detonate that ***** and you get 15000 dead people AND electrical powers aswell. If not gimme a gatling laser

 

[blobin]

either jesus and a pistol to his head

or run down a narrow corridor and get the red faction 2 rail gun