Very small extension to easily convert a Json ActionResult into the object it represents.

WebExtensions.ToJson.cs

using System.Web.Mvc;

public static class WebExtensions
{
     public static T ToJson<T>(this ActionResult actionResult)
     {
         var jsonResult = (JsonResult)actionResult;

         return (T)jsonResult.Data;
     }
}

Usage example:

var myModel = myController.Action().ToJson<MyViewModel>();