Definitely http://worrydream.com http://worrydream.com (Bret Victor's home page). The animated transitions are pretty neat, and were even neater 4 years ago wh

Definitely http://worrydream.com http://worrydream.com (Bret Victor's home page). The animated transitions are pretty neat, and were even neater 4 years ago when he first built them, but my favorite part about the site is the way he lays out his whole design philosophy through a number of well-documented projects.