I have no idea why this one comes to mind, but this is a quote from a movie called "Funny Farm" when the movers are contemplating taking their truck across an old covered bridge.

"That's not a bridge, it's termites holding hands!"

I can't believe someone else has even HEARD of Gummo, let alone quoted it. Possibly one of the most disturbing movies I've ever seen due to its documentary style filming. Great Fight Club quote too!

Ha! I love Funny Farm. It was the beginning of Chevy Chase's fall from grace, but hey, gotta love it anyway.

"We ain't found $#!+!" - Spaceballs.

Also:

"Baby, please! I am not from Havana!" - Blazing Saddles

Zombieguy missed another obvious one - "Send more cops."

The chicks dig me because I rarely wear underwear and when I do it's usually something unusual. Bill Murray (Stripes)

They're coming to get you, Barbara! - Night of the Living Dead

Why is the floor wet Todd?! I don't know Margo!

From Christmas Vacation...when the frozen ice from the gutter went through the neighbors home and melted.

Fear and Loathing in Las Vegas: We can't stop here! This is bat country!

"Like anyone could ever know that Napoleon."

First Jive Dude: Sh-- man, that h---- mus' be messin' my old lady... got to be runnin' cold upside down his head. You know?

Second Jive Dude: Hey home, I can dig it. You know he ain't gonna lay no mo' big rap up on you man.

First Jive Dude: I say hey sky, s'other s'ay I wan say? Second Jive Dude: UH...

First Jive Dude: Pray to J I get the same ol' same ol'.

Second Jive Dude: Eh. Yo knock yourself a pro slick, gray matter live performas down now take TCB'in man.

First Jive Dude: Hey, you know what they say... See a broad, to get that booty yak 'em.

First Jive Dude, Second Jive Dude: Leg 'er down 'n smack 'em yak 'em!

First Jive Dude: Cold got to be. You know? Shiiiiit.

"I must break you" (Rocky IV)

Another from Dazed and Confused "Wipe the face off your head, B*tch!" --Parker Posey as "Darla"

How about the classic, timeless, beaten-into-the-ground and muffled by gunshot "Yippeekay aye, mother f---er"?

Don't know why exactly but a few quotes of one of my favorite American Movies comes to mind. The brilliant and honest evaluation of the human's mind and ego in a fictional way in "The Devil's Advocate":

John Milton: Let me give you a little inside information about God. God likes to watch. He's a prankster. Think about it. He gives man instincts. He gives you this extraordinary gift, and then what does He do, I swear for His own amusement, his own private, cosmic gag reel, He sets the rules in opposition. It's the goof of all time. Look but don't touch. Touch, but don't taste. Taste, don't swallow. Ahaha. And while you're jumpin' from one foot to the next, what is he doing? He's laughin' His sick, f---in' ass off! He's a tight-ass! He's a SADIST! He's an absentee landlord! Worship that? NEVER!

MILTON: Because the law, my boy, puts us into everything. It's the ultimate backstage pass, it's the new priesthood, baby.

MILTON: Free will. It's like butterfly wings.Once touched, they never get off the ground. Free will - it is a bitch.

LOMAX: What about love? MILTON: Overrate. Biochemically no different than eating large quantities of chocolate.

(and my all time favorite) MILTON: Vanity - definitely my favorite sin.

Also from Silence of the Lambs: "You know what you look like to me, with your good bag and your cheap shoes?"

Nothing is over! Nothing! You just don't turn it off! It wasn't my war! You asked me, I didn't ask you! And I did what I had to do to win! But somebody wouldn't let us win! And I come back to the world and I see all those maggots at the airport, protesting me, spitting. Calling me baby killer and all kinds of vile crap! Who are they to protest me? Who are they? Unless they've been me and been there and know what the hell they're yelling about! - First Blood (1982)

Or here's another from the same movie: "You don't seem to want to accept the fact you're dealing with an expert in guerrilla warfare, with a man who's the best, with guns, with knives, with his bare hands. A man who's been trained to ignore pain, ignore weather, to live off the land, to eat things that would make a billy goat puke. In Vietnam his job was to dispose of enemy personnel. To kill! Period! Win by attrition. Well Rambo was the best." - Col. Trautman

"Hungry?" -- last line of "Big Night," followed by an incredibly moving scene with no dialogue as one brother makes breakfast for the other plus another restaurant worker. Astonishingly effective!

Do we have clearence clarence? Roger roger. Whats the vector voctor.

Predator --

"Run !! Go!! .... Get to da Choppa" - Arnold

"There's something out there huntin us, and it ain't no man. We're all gonna die" - Jesse Ventura

Comb the desert! Man we been combin all day, and we aint found sh*t!