Here is the website I took this joke from.
Question: Why did the chicken cross the road?
Pat Buchanan: To steal a job from a decent, hard-working American.
Ronald Reagan: I don't recall.
The Bible: And God came down from the heavens, and He said unto the chicken, "Thou shalt cross the road." And the Chicken crossed the road, and there was much rejoicing.
Richard M. Nixon: The chicken did not cross the road. I repeat, the chicken did not cross the road.
Saddam Hussein: This was an unprovoked act of rebellion and we were quite justified in dropping 50 tons of nerve gas on it.
Dr. Seuss:
Did the chicken cross the road?
Did he cross it with a toad?
Yes! The chicken crossed the road,
but why it crossed it,
I've not been told!
Buddha: If you ask this question, you deny your own chicken nature.
Martin Luther King, Jr.: I envision a world where all chickens will be free to cross roads without having their motives called into question.
Jerry Seinfeld: Why does anyone cross a road? I mean, why doesn't anyone ever think to ask, "What the heck was this chicken doing walking around all over the place anyway?"
The Pope: That is only for God to know.
Grandpa: In my day, we didn't ask why the chicken crossed the road. Someone told us that the chicken had crossed the road, and that was good enough for us.
Colonel Sanders: I missed one?