Bill Cosby
You'd think it'd be the punchline, but apparently it's funnier when the person feints...
Why are all those people running B: They are running a race to get a cup. A: Who will get the cup B: The person who wins. A: Then why are all the others running
She has no arms... Knock knock Who's there Not Suzy
Someone knocking at your door for no apparent reason.
He finishes her drink EDIT: Apparently this is Conan's joke, so all credit goes to him. I just heard it from a friend of mine and I had no idea.
She hits women