Charts.js

Really useful HTML5 Javascript library for making dynamic charts called Charts.js. I think I like this better than Google’s charts.

Update: Sadly this project was taken down by the author due to concerts with IP and their current employer. Hopefully it can be resolved.

Update to the update: Site is back up!

In the mean time here are some alternatives.
Highcharts JS
Flot
NVD3
morris.js
Rickshaw
jqPlot
gRaphaël
YUI charts
Polychart.js