I use this in meetings whenever someone says that they’re sure I’ll agree with them:
“He don’t know me very well, do he?”
Anytime I get something that isn’t to spec: “If I didn’t know this <Hassenfeffer> I’d swear it was carrots!”
From the same square dance:
‘Whirl, whirl, twist and twirl,
Jump around like a flying squirrel!’
[Foghorn Leghorn] Ah’m a horse. Ah say, ah’m a horse. A two-legged horse. That thar’s a chicken. A four-legged chicken. [/Foghorn Leghorn]
Ah, but monsieur is hungry.
I’m a chicken hawk and you’re a chicken.
Emma!
Meep, Meep!
One I use when confronted with antics from one of my dogs.
Foghorn Leghorn: Mutts, Ah say, mutts is nuts!
[Irish Cop Voice] mmmm…you might , rabbit, you might…[/ICV]
I use this on my daughter all the time. Its funnier to me 'cause she is 4 and doesn’t get it. 
Oh- I also find myself singing:
“overture, curtain, lights
this is it, the night of nights…” etc
When we’re about to start something important.
“I can’t help it; I’m a greedy slob! It’s my hobby!”
I tend to sing the following Bugs-used lyrics and confuse the Hell out of people:
…I’m looking over
A three-leaf clover
That I overlooked be-three!
and
…I dream of Jeannie
She’s a light brown hare…
If we’re allowing branch-outs into other cartoon universes, this Woody Woodpecker line pops out of my mouth frequently:
WW: If I’d known you were coming, I’d’ve baked a cake. I haven’t got a cake…but I got a pie!
Tweety is responsible for mine:
“He fall down, go boom!”
“Whaddaya know–no more piddies!”
That dog is about as subtle as a hand grenade in a barrel of oatmeal.
When I encounter someone really stupid (not mentally challenged, mind you - just the type of thick people that occasionaly run the register at Fred Meyer, or fast food joints, etc.) I will quote Beaky Buzzard in my head (or aloud to my wife once we’re out of earshot - she usually smacks me for being rude): “Doo-de-doo-de-doo-doo, doo-doo-doooo, doo-de-doo, de-doo-de-doo-de-doo-dooo.”
But typing doesn’t do it justice. You have to see it here (it starts at 46 seconds in, but the whole clip is worth watching): http://www.youtube.com/watch?v=4LHj2fitPng
And this one doesn’t qualify as a quote per se, but whenever I come across a needlessly complex device, program or process (and in my line of work in sales operations, I see a lot of needless complexity) the factory music from Looney Tunes goes through my head - Powerhouse by Raymond Scott.
And finally - the one sure way to drive my wife crazy is to sing the song from One Froggy Evening - “Hello my baby, hello my honey, hello my ragtime gal. . .” Drives her completely batshit - she once threw a hardcover book at me to get me to shut up.
For the record, the name of that tune is The Arkansas Traveller.
“Da back please, da back.”
“And next time, don’t forget the gravy.”
“Shut up, shutten up.”
And this:
Aaah, your mother rides a vacuum cleaner…
When leaving work, I’ll occasionally tell everyone ‘Nightie niiiggghhht’ in that mad scientist voice.
When donuts are announced in the break room, I’ll sing “Oh, there’s food around the corner, food around the corner, food around the corner for meeeee!”
I have a co-worker named Ralph. Every morning he walks by my desk and says “Mornin’ Biggirl.” and I answer “Mornin’ Ralph-- Mornin’ Sam.” It’s been years and I still don’t think he knows why I do this.
“Ickety ackety oop oh oh squeek ah ah (thbbpt)”
You should see the little dance that goes with it.
I don’t quote Looney Tunes often any more, but when I have the opportunity, I love the line from Duck Dodgers, about his disintegrating ray:
“When I say it disintegrates, by golly, it disintegrates.”
One awkward silence later:
“Well, what do you know, it disintegrated”.
“Tick-tick-tick-tick…<shrugs> It’s a living…tick-tick-tick-tick”
“Cheese? Ah just looove cheese…reaaaaally ah do!”
Ohhhh, Columbus was the discoverer of America
When he sailed the seas in 1492
And the good queen Isabella
Gave her jewels to her fella
So Columbus could sail on the ocean blue!
**
Bugs on the beach: I did it!!! I discovered America!!!
Chris Columbus, up on the hill: Buuugs Buuunnny…Whosa discovered America???
**
Yoiks!..and AWAY!!! (SLAM!) Yoiks…and Away!(SLAM!)[SIZE=“1”]Yoiks, and away…[/SIZE]