If you are into WPF Development and looking for a WPF DataGrid Control, Microsoft has a WPF Toolkit on CodePlex that contains a Free WPF DataGrid Control.
According to the WPF Toolkit Project:
“The WPF Toolkit is a collection of WPF features and components that are being made available outside of the normal .NET Framework ship cycle. The WPF Toolkit not only allows users to get new functionality more quickly, but allows an efficient means for giving feedback to the product team. Many of the features will be released with full source code as well. Over time, some of these features may be moved into the .NET Framework, based on readiness and customer feedback. This is a Community Tech Preview (CTP) Release of the DataGrid control. The download links on this page include a binaries only and a binaries & sources release package...”
If you are doing WPF Development, I recommend checking out the Composite Application Guidance for WPF, which used to be called Prism. You can also check out another open source framework, called Caliburn- an MVP Framework for WPF Composite Applications.
You can download the free WPF DataGrid Control here.