A major part why I love Twin Peaks is the humour. The dialogue is great and there are tons of funny quotes. Here is one for example:
Truman: You were visited by a giant?
Cooper: Yes.
Albert: Any relation to the dwarf?
Post more quotes! (they don't have to be funny, just your favourite ones!)
That is one DAMN fine cup of coffee
The next time you see me, it won't be me.
Using a stuffed animal to represent an endangered species constitutes the supreme...(dramatic pause here)...incongruity.
Either
Leland: GAAAAAAH!! (jumps on the coffin)
or
Cole: There's the One-Armer now!
yup,great quote
"Sometimes the urge to do bad is nearly overpowering."
"Every day holds a new beginning and every hour holds the promise of an Invitation to Love."
Denise: "I still put my panties on one leg at a time, if you know what I mean?"
Coop: "Not really."
(This one just always makes me laugh)
Harry: "The coat was...vicuna."
Gordon: "Sounds real good Sheriff, but I aleady ate!"
Andy: "I'm a whole damn town!" *woo!*
Margaret: "Fire is the devil, hiding like a coward in the smoke."
Doc Hayward: "Hell of a way to kill a tick!"
Jerry: "Would you tell this guy to stop staring at me like I'm a dog biscuit?"
Leo: "New shoes."
Next stop...rocket science!
"Another great moment in law enforcement history!"
Basically take your pick of any line from the Pink Room scene in FWWM
"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this." -Dale Cooper
Cooper: There's a large group of insane men staying on my floor.
Cooper: Diane, I'm holding in my hand a small box of chocolate bunnies.
Achievement is its own reward; pride obscures it.
Coop: Andy, How's the nose?
Andy: Not a mark on it; only blood squirted out.
In the grand design women were drawn from a separate set of blueprints.
"Look, it's trying to think."
Albert to Sheriff Truman.
"I do not suffer fools gladly and fools with badges never. I want no interference from this hulking boob, is that clear?"
As you can tell I love Albert's quotes. 
Cooper: Sure fire cure for a hangover, Harry. You take a glass of nearly frozen unstrained tomato juice. You plop a couple of oysters in there. You drink it down. Breathe deeply. Next you take a mound, and I mean a mound of sweetbreads. Sautee it in some chestnuts and Canadian Bacon. Finally, biscuits, big biscuits, smothered in gravy. Now here's where it gets tricky. You're gonna need some anchovies.
Harry: Excuse me... [runs towards the restrooms]
Cooper: That should do it.
Everything Mike ever says. He is so entirely the man.
"There is no need for medicine. I am not in pain."
Everything Mike ever says. He is so entirely the man.
Mike the OAm or Mike Nelson?
Unnamed Diner: "Hot Damn that pie's good!!!"
this must be where pies go when they die (RR Diner)
Coop: [to Diane] "What really went on between Marilyn Monroe and the Kennedys and who really pulled the trigger on JFK?"
I just love the way he says it, as if nobody's ever really questioned this before.
"Welcome to amateur hour."
Albert, when he is handed the coroner's report from the local lab.
Don't zap the geek!!!