Best Graphic Library to draw simple lines but with a lot of points which changes dynamically! (WPF)

I'd like to know a library to draw graphics in WPF..

I'd like to plot a line graph with a lot of points which increases at runtime.. I tried with DynamicDataDisplay, but it was very slow in my app...

So.. Can you suggest me a library / project to use to solve my problem?

Maaany thanks!

I'd suggest binding your data to a System.Windows.Shapes.Path using a converter, you just need to implement a notifying interface if points are added or removed to update the graph.
(Recently wrote a generic cartesian point array converter for this question)