None. They will never find a bulb that burns as brightly as the old one.
or
Bozo The Clown has real hair on his head.
or
Between you and me, something smells.
or
Only one, but it may take upwards of five years for him to get it done.
or
Nothing, peanuts don't talk.
or
Two. One to exploit the proletariat, and one to control the means of production!
or