In the past 10 years, I was very much influenced by the speeches given by our ex-president Dr.A.P.J Abdul kalam. Unlike other presidents with political background, Dr.Kalam popularly known as “Missile man of India” for his work on development of ballistic missile and space rocket technology. (http://www.abdulkalam.com/kalam/klm-index.jsp) With regards to his speeches, the most noticeable was the one given when he visited my home town (Hyderabad) in India where he talked about “Indomitable Spirit”. It was great experience and made everyone especially the youth/students to think. I could not find the video, but was able to get the transcript of the speech ( http://indianmuslims.in/apj-abdul-kalam-address-at-madina-public-school/) . In this speech, he talks about importance of knowledge which is combination of creativity + righteousness + courage + indomitable spirit. He also stressed on role of creativity and role of teachers in shaping students.
The distinct thing about his speeches is the way he delivers by connecting with the audience. The speech content goes in story telling mode with analogies from real life and also with his distinct poetic quotes empowers with a thought process in the minds of listeners. In some of the videos available on youtube and on his website, he makes audience to repeat his words to leave an importance of the quotes. Another impressive speech was given at the European Union (http://wn.com/Dr_Abdul_Kalam's_speech_in_European_Union) which was acknowledged by union president as one of the inspiring speeches ever heard.
In recent times, I always amazed with speeches by OBAMA who is considered as best speaker in current generation in explaining things