Most badass one-liner ever.

[IsraelRocks]

"I have come here to chew bubblegum and kick ass... and I'm all out of bubblegum."
- Roddy Piper
They Live

First thing that came to mind.
other good ones
"Dodge this"- trinity, the matrix
"i am the law"- Dread

and on the funny side
"did i do that?!!?" steve urkel

 

[Crazy_Dude]

"Ninjas damn"

 

[Engarde]

That's not a knife......that's a knife.

 

[Bloodastral]

The Karate Kid "Wax on, Wax off".

 

[Amyler]

"Hello. My name is Inigo Montoya. You killed my father. Prepare to die."
- Inigo Montoya, The Princess Bride

Tarnations, ninja'd. Well, from the same movie, then!

"Are you just messing around with me or what?"
"I just want you to feel you are doing well. I hate for people to die embarrased."
Oh Fezzik, you so wonderful.

 

[gibboss28]

"Who ordered the Kick-Ass fajitas?"

-Romeo
Boondock Saints 2: All Saints Day.

I prefer the other one:

 

[Elementary - Dear Watson]

"WE ARE SEX BOB-OMB, AND WE ARE HERE TO WATCH SCOTT PILGRIM KICK YOUR TEETH IN- 1-2-3-4!!!"

Epic... Truly Legendary Epic!


Oh, and "I hope I give you the sh*ts..." - Spoon, in Dog Soldiers

 

[RYjet911]

"I have come here to chew bubblegum and kick ass... and I'm all out of bubblegum."
- Roddy Piper
They Live

"I came here to drink milk, and kick ass... And I just finished my milk."
- Maurice Moss, The IT Crowd
http://www.youtube.com/watch?v=RG1mEk5E-1k

 

[GodofDisaster]

"Now go give that Mare boy a scare"

Vongola primo to Tsuna during the main villain's defeat.

(Hitman reborn)

I'm not sure of this counts as a one liner but it's badass nonetheless.

"GIGA DRILL BREAKER!!" various characters use that move, in the anime Gurren Lagann.

 

[Zeromaeus]

Hardly the most badass ever, but:
'We were told you'd been fatally wounded!'
'Yes. I'd been told that as well. I chose to ignore it and continue living.'

Most badass ever goes to Tengen Toppa Gurren-Lagann:
'Go beyond the impossible and kick reason to the curb!'
'Yours is the drill that will pierce the heavens!'
'WHO THE HELL DO YOU THINK WE ARE!?!'

 

[DazBurger]

Cannot be denied!
[HEADING=3]THIS![/HEADING]

 

[WOPR]

What is the most bad ass one-liner you have ever heard?

"I have to kill fast and bullets too slow!"
-John Freeman
Half Life: Full Life Consequences: Free Man

*shoots guy 6 times*
"I CHALLENGE YOU!"

-Turquoize

EDIT: on second though

YOU, SHALL NOT, PASS!

 

[ComicsAreWeird]

«WELCOME..TO DIE!!»

 

[Elemental]

"Eat boot!"
Gears 2

 

[TheJayke]

*shoots guy*
*turns to other*
"Oh i'm sorry did I break your concentration?"

Pulp Fiction <3
I like..
Vincent: Ah man I just shot Marvin in the face.
Jules: Why the fuck did you do that?!
Vincent: I didn't mean to do it, it was an accident!


And Scarface..
"Say hello to my lil friend!"
*Pulls out grenade launcher*

 

[WanderingBiscuits]

Bad Guy "Please spare my life!! I can provide with a high paying position in my company!!"

Jason Statham "I've got a position for you....Permanently disabled"

Then he tosses him off a train

Forget which film

 

[JacobyPAX]

From Doomsday Arcade Episode 7
"I'm mysterious- Dickhead."

 

[dmjewelle]

"Reinforcements? I AM the reinforcements."
- Ashley Riot, Vagrant Story

 

[Wutaiflea]

Distressingly, I couldn't find a clip to accompany it, but I've always been a fan of Sean Connery's James Bond one-liners, particularly...

"Shocking."

After electrocuting someone (I forget which of the billion Bond films this was). His delivery was just awesome.

 

[Bernzz]

"They are sinking cities with a giant worm!"
- Gears of War 2

I laughed so hard. That line just...the yelling just came out stupid. I replay the level sometimes just for that scene.

For me?

"Communism is DEATH!"
- Liberty Prime, Fallout 3.