Perhaps its unfair to use a Monty Python film because they came up with fifty brilliant lines before breakfast:

"Strange women lying around in ponds handing out swords handing out swords is hardly the basis for a system of government."

Of Course Billy Wilder is fairer:

"You don't understand. I'm a man!"

"Well, nobody's perfect."

Best. Last line. Ever.

A little darker from Ace in the Hole:

"I don't go to church. Kneeling bags my nylons."

From To Be or Not To Be (this is actually darker)

"I saw him in Hamlet. What he did to Shakespeare we are now doing to Poland.

And of Course from Mel Brooks:

"I said across her nose, not up it!"

(Or basically any of the lines from that section of Spaceballs.)

Love Actually from hugh Grant to Margaret Thatcher:

"Did you ever have to deal with? What am I saying? of course, you did you saucy minx."

Many of these lines are, of course, situational. So let's close with Groucho Marx:

"You know you haven't stopped talking since I got here, you must have been vaccinated with a phonograph needle.