Ok so I recently got a request to do a project that uses all kinds of pretty charts, and initially the development team wanted to use Open Flash Charts, but the developer I was working with on the project was on leave for two days and in that time I decided to check out New ASP.NET Charting Control:
You then have access to a range of classes by typing the fully qualified namespace like this:
System.Web.UI.DataVisualization
Once you have access to the classes you can do all sorts of interesting things. You get to choose from 35 different chart types, that you can format with colours, 3D effects. And you can also use data with it very easily with a datareader, which impressed me. You can also save your charts as images.