I have used the Report Viewer Control included in Visual Studio 2005 to embed reports within our Smart Client. The control allows me to create professional reports without the use of a third party tools. Plus I can always scale up to Reporting Services should the need arrise.
There is a Report Viewer Redistributable available for download. However, the Redistributable is an MSI and installs all components in the GAC. This action requires administrator permissions which is not a choice due to our corporate security policy.