Regis Philbin is sitting in for Piers Morgan tonight on his CNN show. And Reeg called in the big gun, David Letterman, who rarely does TV outside of his own show. Regis asked Dave who his favorite guests have been over the years.

“We have several – you, Brian Williams, Tom Brokaw, Bill Murray, Tom Hanks, people who really come and do a great job for us.”

“You know that Brian Williams wants your job,” said Regis. “Brian Williams can have my job,” Letterman shot back.

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