Dad jokes? My fave is:
Why do seagulls fly over the ocean? Because if they flew over the bay we'd call them bagels.
Otherwise (since Az stole my fave )...
A rabbi, a priest and a minister are discussing when life begins.
The priest says: "In our religion, life begins at conception."
The minister says: "We disagree. We believe that life begins when the fetus is viable outside of the mother's womb."
The two argue for a couple of hours then suddenly realized they were being rude to the rabbi. They apologized profusely and ask him the question.
The rabbi put down his newspaper, and after some thought answered, "For us, life begins when all of the children finish college, get a job, leave home and take the dog with them."