American Rhetoric is an incredible site and there are some real gems that aspire to rational persuasion with some flair.

<http://www.americanrhetoric.com/top100speechesall.html>

Malcolm X's "Ballot or the Bullet" navigates the fact that he is black, widely regarded as dangerous and Muslim all at once while urging people to put these things aside and think about his plans and their outcomes. He does a first rate job of tailoring his rhetoric to increase your emotional desire to think and not react.

Milton Friedman is another person to watch live. He gets a bad rap from people who don't watch him, but if you have ever heard him speak, he excels at softly thinking through positions with the listener while still taking bold positions.

<http://www.youtube.com/watch?v=JfdRpyfEmBE&feature=player_embedded>

They said it best in Howard Stern Private Parts:

"I want to hear what he'll say next."

Gladwell is probably the best for presenting fact and figures in speeches. You might not like his numbers or rigor, but his presentatoon methods are top notch, often focused on challenging his listeners beliefs with academic research:

<http://video.google.com/videoplay?docid=6204900041349106153&ei=YRTDSerTM4qIqwLbn9yuCw&q=Gladwell&hl=en>