<customErrors mode="On" defaultRedirect="Error.aspx">
  <error statusCode="403" redirect="NoAccess.htm"/>
  <error statusCode="404" redirect="FileNotFound.htm"/>
</customErrors>

and put [HandleError] above my Controller Class like this:

[HandleError]
    public class DSWebsiteController : Controller { [snip] public ActionResult CrashTest() { throw new Exception("Oh Noes!"); } }

Then I let my controllers inherit from this class and call CrashTest() on them. Visual studio halts at the error and after pressing f5 to continue, I get rerouted to Error.aspx?aspxerrorpath=/sxi.mvc/CrashTest (where sxi is the name of the used controller. Off course the path cannot be found and I get "Server Error in '/' Application." 404.