On Monday night's episode of the "Late Show," Barack Obama became the first sitting U.S. president in history to appear as a guest on David Letterman's program. Letterman presented a humorous top 10 list to explain the president's surprising decision to accept the invitation. Among the reasons, Letterman joked that he impulsively said yes "like Bush did with Iraq." Obama had his own motives for making an appearance on one of television's most-watched late night programs. "The main reason I'm here? I want to see that heart-shaped potato." Agree with his policies, or not, our leader certainly does have quite the sense of humor. David Letterman's "Late Show" has ranked #1 among late night programs for ten consecutive weeks. With guests like Barack Obama, one of the most respected and powerful men in the world, it's no surprise.