Oh man! As a TEDx organizer and as a general fan, I've been waiting for this question all my life.
Let's break this up a bit.
- In the mood to see demographic data come to life in front of you?
It's the talk I send people to introduce them to TED. A classic.
- In the mood to learn something new about music and be inspired?
The second talk I send people. Just an incredible speaker, I've never met someone who didn't love this talk. Got me to listen to classical music in a whole new way.
- In the mood to feel excited about the education system?
My favorite talk ever. Bill Gates comes on at the end and calls his method the "future of education." If you like data/engineering, you're especially likely to fall in love this this video.
- In the mood to wonder at the mysterious nature of the human brain?
One of the talks to put TED on the map. Harvard neuroscientist happens to gets a stroke, achieves a nirvana-like state, and then studies what happened to her to figure it out.
- In the mood to laugh and also reflect on how schools work and don't?
Another classic TED talk, Robinson discusses the importance of creativity. The talk is both charming and deeply thoughtful.
- In the mood to reconsider how society treats creativity?
Another classic, the top talk for people interested in writing/the arts. Basically, we pressure artists in subtle and unfair ways with our modern conception of what it means to be a 'genius.'
- In the mood to watch an incredible tech demo?
I don't know what's happened to this since then, but this technology was all the buzz when the talk came out. The MIT Media lab has a lot of good talks - I recommend the "Siftables" talk as well.
- In the mood to smile and laugh at clever advertising?
One of my very favorite talks, it's a clever look at how advertisers actually add value to the world. Also, hilarious. I recommend his other talk as well.
- Interested in thinking about the role of women in business?
One of the most discerning discussions of the state of women in society I've seen, by the COO of Facebook. Discusses the reasons that women hurt themselves professionally, encourages them to take charge.
- In the mood to think about the dynamics of peace negotiations / be inspired?
On how to "get to yes" in a negotiation. Good stuff.
- In the mood to just be entertained with some sweet juggling?
An old one. Long, but worth it - the 'father of juggling' does some crazy stuff.
- In the mood to see a talk about Reddit?
Can't leave this one out of this list!
There are many, many more, but this is more than a good start.