Bingo!
I only know one: Men in Black. Have often wondered what it’s a reference to.
Them!.
The Sting, where it actually is the punchline of a joke told by Leonard Barr onstage at the burlesque joint.
Shawn of the Dead. One of my favorites!
Lion in Winter.
“This is the Voice of Doom calling. Your days are numbered, to the seventh son of the seventh son.”
Mine too. 
I don’t know if I’m allowed to post as I haven’t guessed any, but how about this one:
“There really is nothing like a shorn scrotum, it’s breathtaking, I suggest you try it.”
Austin Powers, International Man of Mystery
And, since nobody’s gotten it yet, here’s mine again:
“I thought I was dead, but it turned out I was in Nebraska.”
“Don’t ever hit your mother with a shovel. It will leave a dull impression on her mind.”
Yes, but did you know Newman also said it as Hank Stamper in Sometimes A Great Notion?
Unforgiven.
“Obviously, you’re not a golfer.”
The Big Lebowski. The one movie absolutely certain to appear in a thread like this one.
“There was only one problem. I’d never been in love.”
Moulin Rouge (the Ewan McGregor version)
[going into a funeral]
“Here… cover up your titties LaVonda…”
Yep thats the one. The line that starts the mud pit fight.
“Gesundheit!”
“You may go now.”
“Maybe he just wanted to steal our wirecutters, ya ever think of that?”
“Nine years of ballet, asshole!!”
One of my favorites- Stalag 17
Maybe that’s why we always wear our hats.
“I’m not even supposed to be here!”
“Who are those guys?”
Clerks, and it’s “I’m not even supposed to be here today!”
“Lookin’s free, but touching’s gonna cost ya.”