I implemented amCharts earlier this year on an internal project. The version we used is not rendered in flash. They use SVG (and VML for IE6-8 support). Been very pleased with their look/feel and feature set. The documentation on their site was organized and helpful. Concluded on amCharts as a result of a personal analysis of eight charting libraries. amCharts does allow free (with conditions, link) and pay options.
I think highcharts is a top contender but ultimately felt amCharts had better aesthetics. The updated highcharts is certainly looking good.
I think highcharts is a top contender but ultimately felt amCharts had better aesthetics. The updated highcharts is certainly looking good.
(here was the analysis breakdown done in February 2014: http://i.stack.imgur.com/efgoR.png)