I've always found the talk "Adam Savage's Obsessions" to be inspiring. His eye for detail and relentless obsession for getting things right are contagious. http://www.ted.com/index.php/talks/adam_savage_s_obsessions....
For me, it's a toss up between Adam's talk and Mike Rowe's talk.
The best part about Adam is his amazing energy and enthusiasm for everything he does.
I enjoyed Daniel Kahneman on "The riddle of experience vs memory", which is about the ways people structure their lives for experiences they think they will enjoy remembering, rather than things they'd necessarily enjoy doing at the time. There's also a good anecdote about how making a colonoscopy slightly more unpleasant cam leave the patient with a more favorable recollection.
Paul Stamets on 6 ways mushrooms can save the world: http://www.ted.com/talks/paul_stamets_on_6_ways_mushrooms_ca... This talk is not about hallucinogenic mushrooms. It really opened my eyes to the awesome potential of fungi, and how this potential is largely ignored because of the connotation to "hippy" and "drugs." Fungi is just generally misunderstood. I was absolutely amazed at how thorough these clean-up jobs we…
I have to concur in a comment here because this TED talk was so mind blowing for me I feel I need to write down my opinions about it somewhere. The way this guy talks about mushrooms is extremely earnest and its clear he's both incredibly knowledgeable and passionate about his field. It's almost as though he can't get the information out of his mouth and into the crowd fast enough, and what's more is that he speaks like he has discovered and is revealing for the first time the world's most incredible secrets - which in a way he is. It's not over dramatic, just genuine and awesome. Watch this video!
http://www.ted.com/talks/vilayanur_ramachandran_on_your_mind... ("Vilayanur Ramachandran tells us what brain damage can reveal about the connection between celebral tissue and the mind, using three startling delusions as examples. .. Dr Ramachandran is the author of the author of Phantoms in the Brain (the basis for a Nova special), A Brief Tour of Human Consciousness and The Man with the Phantom Twin: Adventures in…
This is also my favorite TED talk. Ramachandran has come up with some clever ways to study and heal the brain. His mirror box therapy is not only simple and effective, but his prerequisite theory was accurate yet initially based on a tiny amount of evidence.
I enjoyed all three of Juan Enriquez's talks, Kevin Kelly on how technology evolves and Ray Kurzweil on how technology will transform us. Together, those 5 talks greatly changed the way I view the world.