Well, Kelly's Heroes, A League of Their Own, Young Frankenstein, and Princess Bride come to mind...take your pick of almost any scene.

I'll toss out the first gauntlet....

http://www.youtube.com/watch?v=mC-mO-WtVJo

You're gonna need a bigger boat. - Jaws

http://www.youtube.com/watch?v=8gciFoEbOA8&feature=related

It's just a flesh wound. - Black Knight

Monty Python and the Holy Grail

http://www.youtube.com/watch?v=2eMkth8FWno

"Toto, I've got a feeling we're not in Kansas anymore." Dorothy Gale

Wizard of Oz

http://www.youtube.com/watch?v=EPWenQxryr4

"Obviously, you're not a golfer."

The Big Lebowski.

http://www.youtube.com/watch?v=GvnhNeHAafg

From Jurassic Park:

[Malcolm walks up to a huge mound of dino-droppings]
Dr. Ian Malcolm: That is one big pile of shit.

http://www.youtube.com/watch?v=qOtTWSpCa_c

From A Fish Called Wanda.

[Otto dangles Archie out a window]
Archie: All right, all right, I apologise.
Otto: You're really sorry.
Archie: I'm really really sorry, I apologise unreservedly.
Otto: You take it back.
Archie: I do, I offer a complete and utter retraction. The imputation was totally without basis in fact, and was in no way fair comment, and was motivated purely by malice, and I deeply regret any distress that my comments may have caused you, or your family, and I hereby undertake not to repeat any such slander at any time in the future.
Otto: OK.

http://www.youtube.com/watch?v=m7mIy97_rlo&NR=1

"You didn't think it would be that easy, did you?"- Oren Ishii

" You know for a second there, yea, I kinda did"- The Bride, Kill Bill

From the scene right before she has to fight the entire crazy 88 gang...

the scene is @ the 4:12 mark

http://www.youtube.com/watch?v=a3aFv8IQb4s&feature=related

"Well there's something you don't see every day."

-Peter Venkman, "Ghostbusters"

http://www.youtube.com/watch?v=d-sALU_hveA

Wow, looks like we might be on track for another 2 weeks worth of quotes. TBD based on other suggestions.

"You met me at a very strange time in my life" (Fight Club)

"I've had a rough year Dad" (Royal Tenenbaums)http://www.youtube.com/watch?v=KtiowtWMHxI

Two most poignant I could think of.

How about the exchange after Garth's wicked drum solo in Wayne's World?

Guy: Wow. You're... amazing, dude.
Garth: Thanks. I like to play.

http://www.youtube.com/watch?v=7g3RGtBTbt4

2001: A Space Odyssey screenplay by Stanley Kubrick and Arthur C. Clarke

Just what do you think you're doing, Dave? Dave, I really think I'm entitled to an answer to that question. I know everything hasn't been quite right with me, but I can assure you now, very confidently, that it's going to be all right again. I feel much better now. I really do. Look, Dave, I can see you're really upset about this. I honestly think you ought to sit down calmly, take a stress pill and think things over. I know I've made some very poor decisions recently, but I can give you my complete assurance that my work will be back to normal.

http://www.youtube.com/watch?v=ukeHdiszZmE

Colonel Lucas: Your mission is to proceed up the Nung River in a Navy patrol boat. Pick up Colonel Kurtz's path at Nu Mung Ba, follow it and learn what you can along the way. When you find the Colonel, infiltrate his team by whatever means available and terminate the Colonel's command.

Willard: Terminate the Colonel?

General Corman: He's out there operating without any decent restraint, totally beyond the pale of any acceptable human conduct. And he is still in the field commanding troops.

Civilian: Terminate with extreme prejudice.

[can't find clip]


Don Corleone: I'm gonna make him an offer he can't refuse.

http://www.youtube.com/watch?v=SeldwfOwuL8