What are your favorite nuget mvc packages

What are your favorite MVC packages available on Nuget? Why?

Here are the most common ones I end up installing in a new MVC Application:

  • Elmah - Great for capturing errors (I usually install Elmah for Glimpse as well)
  • Glimpse - Great for monitoring routes and tracing information.
  • RazorGenerator - Precompiled views, compile time checking
  • Mini-Profiler - Awesome little way to profile MVC without much overhead.
  • Markdown-Deep - Since most of my sites utilize user input and I would prefer not to allow html input I use this.
  • Json.Net - Fast Json library.
  • Errlusion - My own little configuration-less error handler for MVC.
  • DotNetOpenAuth - I use this for user authentication. I'd rather not maintain credentials on my sites.