Microsoft actually licensed some code from Dundas and produced avery good set of free charting controls based on that code.
To download the controls:
http://www.microsoft.com/downloads/details.aspx?FamilyId=130F7986-BF49-4FE5-9CA8-910AE6EA442C&displaylang=enSamples:
http://code.msdn.microsoft.com/mschart