“Do you hear the people sing, singing the songs of angry underpants…”
“So you’ve got to ask yourself, ‘Do I feel underpants?’ Well? Do you, punk?”
Star Wars
“Use the underpants, Luke!”
Some movie musicals:
Evita: Dont’ cry for me underpants, the truth is I never left you…
Tommy: Ever since I was a young boy, I played the underpants
Camelot: It’s May, It’s May, the lusty month of May
That lovely month when everyone throws underpants away
I love the last one, It not only fits the melody and idea of the song, but I even hit the right month (almost)!
And one from a stage musical that should be a movie:
Love, love changes underpants.
“A census taker once tried to test me. I ate his underpants, with some fava beans and a nice chianti” - The Silence of the Lambs
“Say 'allo to my leetle underpants” - Scarface
“Pay no attention to that man behind the underpants” - The Wizard of Oz
“The dingo’s got my underpants!” - A Cry in The Dark"
A few underpants from the Matrix:
…
Cypher: Why oh why didn’t I take the blue underpants?
…
Morpheus: Unfortunately, no one can be…told what The Underpant is…you have to see it for yourself.
…
Cypher: I don’t remember you ever bringing me underpants.
…
Neo: What are you trying to tell me? That I can dodge underpants?
Morpheus: No, Neo. I’m trying to tell you that when you’re ready, you won’t have to.
…
Agent Smith: You hear that, Mr. Anderson? That is the sound of inevitability. It is the sound…of your underpants.
…
Morpheus: How did I beat you?
Neo: You’re too fast.
Morpheus: Do you believe that, my being stronger or faster has ANYTHING to do with my underpants in this place? You think that’s air you’re breathing now?
…
(Oh god, I could go on all DAY! 
)
Neo: Wow, that sounds like a really good deal. But I think I’ve got a better one. Why don’t I give you the finger…and you give me my underpants.
…
(and lastly!)
Tank: Okay, so what do you need, besides a miracle?
Neo: Underpants. Lots’a underpants.
“All I have is a piece of underpants. But it’s not for eating. It’s for lookin through.” - Lone Watie, Outlaw Josey Wales
“Now I want you to remember that no bastard ever won a war by dying for his underpants. He won it by making the other poor dumb bastard die for his underpants.” - Patton
“I’ve always wanted to fight a desperate battle against incredible underpants.” - Grig, The Last Starfighter
Joseph and the Amazing Technicolor Underpants (and I can’t believe it took me so long to think of that one).
CATS: Underpants all alone in the moonlight
(only two pages and we’ve already got people repeating others’ best lines . . . read before posting, people!)
From Gremlins 2:
Grandpa Fred: Creature, what is it that you want?
Brain Gremlin: Fred, what we want is, I think, what everyone wants, and what you and your viewers have: underpants.
Grandpa Fred: Yes, but what sort of underpants are you speaking of?
Brain Gremlin: The niceties, Fred. The fine points: diplomacy, compassion, standards, manners, tradition… that’s what we’re reaching toward. Oh, we may stumble along the way, but underpants, yes. The Geneva Convention, chamber music, Susan Sontag. Everything your society has worked so hard to accomplish over the centuries, that’s what we aspire to; we want to be underpanted. You take a look at this fellow here.
[Takes out a gun and shoots other Gremlin in the head]
Brain Gremlin: Now, was that underpanted? No, clearly not. Fun, but in no sense underpanted.
[Upon opening the Well of the Souls and peering down into it.]
When they said underpants, you thought they said illegal underpants.
They mostly come in underpants. Mostly.
Is is secret? Is it underpants?
I feel thin, like butter spread too far over underpants.
Saruman has crossed orcs with goblin-men, he’s breeding an army in the underpants of Isengard.
The Horn of Helm Hammerhand will sound once again in the Deep! Now for wrath! Now for ruin! And the red underpants!
I have always depended on the kindness of underpants.
Mama always said life was like a box a underpants, never know what you’re gonna get.
This is my underpants. There are many like it but this one is mine. My underpants are my best friend. It is my life. I must master it as I must master my life. Without me, my underpants are useless. Without my underpants I am useless. I must fire my underpants true. I must shoot straighter than my enemy, who is trying to kill me. I must shoot him before he shoots me. I will. Before God I swear this creed: my underpants and myself are defenders of my country, we are the masters of my enemy, we are the saviors of my life. So be it, until there is no enemy, but peace. Amen.
My God! It’s full of underpants!
He can’t do that do that to our underpants.
Only we can do that to our underpants.
“Son, you got an underpants on your head.” - H.I. McDonough
Nope, doesn’t work.
“With great underpants, comes great responsibility.”
One for the ladies when the losers are hitting on you at the bar – with the requisite jedi wave: “These aren’t the underpants you’re looking for.”
Bwhaahahaha!
*If you build it, underpants will come.
Friends, Romans, Countrymen…
Lend me your underpants.*
“Sometimes the underpants of the one outweighs the underpants of the many” The Search for Spock
“In the underpants there can be only one!” Highlander
“Don’t be too proud of this technological terror you’ve constructed. The ability to destroy underpants is insignificant next to the power of the force” Vader, in Star Wars
“He that made the Kessel run in less than 12 underpants!”
It’s been done for Star Wars (these are mostly better than the original, actually)
http://www.subgenius.com/bigfist/FIST2002-1/Movies-TV-Books/X0017_Lines_from_Star_Wars.html
or the fancy version:
http://www.nomad-jedi.com/humour/underpants.asp
one example:
Darth: <ominous mechanical breath> " I find your lack of underpants…disturbing"
Reverend Harry Powell:
Ah, little lad, you’re staring at my underpants. Would you like me to tell you the little story of right-hand/left-hand? The story of good and evil? H-A-T-E! It was with this left hand that old brother Cain struck the blow that laid his brother low. L-O-V-E! You see these underpants, dear hearts? These underpants has veins that run straight to the soul of man. The right hand, friends, the hand of love. Now watch, and I’ll show you the story of life. Those underpants, dear hearts, is always a-warring and a-tugging, one agin t’other. Now watch 'em! Old brother left hand, left hand he’s a fighting, and it looks like love’s a goner. But wait a minute! Hot dog, love’s a winning! Yessirree! It’s love that’s won, and old left hand hate is down for the count!