I think my favorite (tied with George Carlin & Stephen Wright), is Sam Kinison, (I took out the cuss words):
"You want to help world hunger? Stop sending them food. Don't send them another bite, send them U-Hauls. Send them a guy that says, "You know, we've been coming here giving you food for about 35 years now and we were driving through the desert, and we realized there wouldn't BE world hunger if you people would live where the FOOD IS! YOU LIVE IN A DESERT!! UNDERSTAND THAT? YOU LIVE IN A DESERT!! NOTHING GROWS HERE! NOTHING'S GONNA GROW HERE! Come here, you see this? This is sand. You know what it's gonna be 100 years from now? IT'S GONNA BE SAND!! YOU LIVE IN A DESERT! We have deserts in America, we just don't live in them!"