The Turing Award lectures make great reading, and a Google Search will turn up some of them. The rest can be accessed via Association For Computing Machinery's (non-free) Digital Library. Also see the book The Acm Turing Award Lectures.
Some Turing Award lectures discussed on this Wiki (Clicking on the page title link above may help to reveal more.):
Alan Kay Turing Award Lecture: "First Courses In Computing Should Be Childs Play"
All of these are on the web.
See original on c2.com 