Who is the best presenter? Who is the worst presenter? Why?

The worst presenter is microsoft dude. He keep on crossing his arms during presentation. This might make the audience feel they are unrespected by the presenter. In the point of view of phsycology, when a people always cross his or her arms, it means he or she is confident with himself. Besides, the way of the microsoft dude did the presentation have let me felt that he is not prepared. He got butterflies on his stomach. That's why he is the worst presenter .
The best presenter is Randy Paunsch, giving a talk 'the last lecture'. He starts it with the disease he face. He did not give up with his life and try to bring happiness to audience. He shared his childhood dreams and how he do to achieve it. He even shared his experience of being scold by his coach. In his presentation, he ask us to be happy and enjoy life. This makes me feel that nothing is impossible. His speech makes me touch and let me realised that 'don't worry, be happy' is the way we enjoyed our life. So friends, let us succeed our dream together and bear in mind they is always got solution to solve the problem, no matter how difficult is the task, please don't give up!!!!