Badass Line as you kill...

[Baldry]

"I'm here to kick ass and drink milk...And i'm all out of milk"

"I'm here to chew ass and eat bubblegum....and i'm all out of ass...wait that's not right"

Or

"The path to a man's heart is through his stomach...Lets see if that's true *uppercut through stomach and rip out heart* Hm guess it is."

 

[gamefreakbsp]

Adios Mother Fucker!!!!!

 

[gamefreakbsp]

One of these bullets has your name on it, and I'm going to keep shooting until I figure out which one it is."

Heheheh. This is the best one yet.

 

[MercurySteam]

One of these bullets has your name on it, and I'm going to keep shooting until I figure out which one it is."

Indeed:

For me personally: "Yippee ki-ay, ************!"
It works wonders in BF:BC2.

 

[ddon]

"I would have killed you with a tray but I couldn't find one, so this will just have to do."

 

[FightThePower]

'Sit down.'

 

[midevilmonkey0]

Either "Bang!" or "ENCHANTMENT!"

 

[Steve Butts]

"See you in Hell...from HEAVEN!"

 

[Th37thTrump3t]

Or.....

"In nomine Patris, et Filii, et Spiritus Sancti."

Who ever gets this gets BadAss points.

In the name of the Father, Son, and Holy Spirit. Not hard.

 

[runnernda]

Excellent use of source material. "All the birds are singin' that you're gonna DIE."

I tend to just say something along the lines of "WHAT NOW, *****?" or "OH SHIT SON!" I become inexplicably gangsta when I game.

 

[Baron von Blitztank]

"Sir! Sir, please, Sir! Sir, I need your brain. No sir, you don't understand, Please, Sir, stop running Sir, I need your brain!"
*BANG*
"Thank you sir, that wasn't so hard was it?"

 

[the fake]

go to hell! and tell the devil im comin for him next!

 

[Deadlock Radium]

I kill them first then yell the following:
[HEADING=2]BOOM![/HEADING]

 

[Terror_666]

My personal favorite is "HAHAHA! Fuck you."
The laughing in a somewhat maniacal tone followed by a very dry deadpan tone.

 

[myxomitosis87]

"Yippe Kay-Yay ************" or if I was a priest; "God has mercy, I don't."
Or just to confuse him; "Elvis didn't do no drugs!!!"

 

[Broken Orange]

"I am going to kill you till you die from it!"

Hot Shots 2 is just that awesome.

 

[Doomsday11]

I have stood and watched world's burn and civilizations crumble and you dare defy me!

 

[sageoftruth]

Say "hi" to my ex for me.
*bang*
Lucky bastard.