I wanted to set a CSS class in my master page, which depends on the current controller and action. I can get to the current controller via ViewContext.Controller.GetTy
ViewContext.Controller.GetTy
I am using ASP.NET MVC 4, and this what worked for me:
ControllerContext.Controller.ValueProvider.GetValue("controller").RawValue ControllerContext.Controller.ValueProvider.GetValue("action").RawValue