Best last words.

[Doctor X.]

Best last words from someone who expired immediately after saying them, movie of TV.

Star trek. Journey to babel. Orion spy disguised as an andorian after stating he had taken poison and guessed he had ~10 minutes left.- "Uh! I seem to..have ...miscalculated."

Lifeforce. Dr. Fallada just before experiencing what he'd spent his life studying; "Here I go!"

Star trek. Balance of terror. Romulan captain. "Just one more duty to preform."

The last starfighter, enemy ship captain just before his ship crashes. "We die."

[Umaril The Unfeathered]

The first Child's Play as Chucky is begging for his life.

"Andy, you and I, were friends to the end!"

Andy looks at him and says, "this IS the end", and lights Chucky on fire.

[Jim H]

From Heist:

"Don't you want to hear my last words?"

"I just did"

*BANG*

[Raffine]

"We belong dead."
The Monster (Karloff)
BRIDE OF FRANKENSTEIN

[bumblefish]

I just wanted to sail around the world, watch the dolphins, maybe shoot a couple of em.
The big hit. lou diamond philips

[retrorussell]

"Sayonara Robocop!!!"
--Boddicker, before Robocop stabs him in the neck

"You have won NOTHING!"
--Damien, to a statue of Jesus in The Final Conflict: Omen III

"Those cookies sure were good."
--Kitano-sensei as he collapses from a hail of bullets in Battle Royale

[Trevor]

Ned Beatty in Shooter to Mark Walhberg: "I am a United States Senator!!"

Walhberg: "Exactly." [shoots him in the head]

[Jack]

"You cursed brat! Look what you've done! I'm melting! melting! Oh, what a world! What a world! Who would have thought a good little girl like you could destroy my beautiful wickedness? Oooooh, look out! I'm going! Oooooh! Ooooooh!" 
   - Wicked Witch of the West, Wizard of Oz.

[Umaril The Unfeathered]

Cemetery Man where the Mayor of the town crawls out of his grave and tries to escape the cemetery.  Dellamorte (Rupert Everett)  tells him to get back in his grave.

The zombie says "you can't order me around, engineer, I'm the mayor of this town!"

Dellamorte shoots him in the head, and says "Ex-mayor.

[Rev. Powell]

"I used... preservatives."

[Allhallowsday]

BLAZING SADDLES: HARVEY KORMAN, fatally shot, looks down at DOUGLAS FAIRBANK's footprints in cement and marvels: "How did he do such spectacular stunts... with such... tiny feet?!"

[Umaril The Unfeathered]

Red Dawn where C. Thomas Howell's character, trapped and having nowehere to go, takes the sash off of his face, and stands in defiance and raises his AK-47 to an incoming MI-24 Hind chopper.

He screams out "Wolverines!!!" as he fires at the chopper, as he goes down in a blaze of Red White and Blue glory. 

The scene got major yells and cheers from the audience.

[ChaosTheory]

"Larry, stop pointing that f*ckin' gun at my dad!" - - Nice Guy Eddie (Chri s Penn), Reservoir Dogs

"I feel....cold...." Barbosa (Geoffrey Rush), POTC, Curse of the Black Pearl

In The Hitcher remake, when Sophia Bush's character finally has the Hitcher (Sean Bean) beat, right before she shoots him he looks up and whispers, "Feels good, doesn't it?"

[retrorussell]

I AM INVINCIBLE!!!
Boris, before being put into permanent deep-freeze in Goldeneye

[Umaril The Unfeathered]

And lest we forget our old friend James Cagney in White Heat just before his death atop the gasoline tanks in the refinery.

"Top O' the world, Ma!!!"