1) Amazing game developed with html5 (without any flash)

asteroids

http://www.kevs3d.co.uk/dev/asteroids/

2) 12 Examples

http://htmlfive.appspot.com/

3) HTML5 Demos

http://html5demos.com/

4) HTML5 Image uploader

upload

http://demos.hacks.mozilla.org/openweb/imageUploader/

5) A list of html5 bookmarking

http://delicious.com/khalweir/html5

6) A good HTML5 implementation

car

http://www.nissanusa.com/leaf-electric-car/

7) Basic video player

video

http://htmlfive.appspot.com/static/video.html

8) A simple game

game

http://www.benjoffe.com/code/games/torus/

9) A good presentation

http://apirocks.com/html5/html5.html#slide1