MVC Enum Helper (via http://blogs.msdn.com/b/stuartleeks/archive/2010/05/21/asp-net-mvc-creating-a-dropdownlist-helper-for-enums.aspx)

MVCEnumHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Html;

namespace MyProject.Helpers
{
    public static class EnumHelpers
    {
        public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TEnum>> expression)
        {
            ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
            Type enumType = GetNonNullableModelType(metadata);
            IEnumerable<TEnum> values = Enum.GetValues(enumType).Cast<TEnum>();

            IEnumerable<SelectListItem> items =
                values.Select(value => new SelectListItem
                {
                    Text = value.ToString(),
                    Value = value.ToString(),
                    Selected = value.Equals(metadata.Model)
                });

            if (metadata.IsNullableValueType)
            {
                items = SingleEmptyItem.Concat(items);
            }

            return htmlHelper.DropDownListFor(
                expression,
                items
                );
        }

        private static Type GetNonNullableModelType(ModelMetadata modelMetadata)
        {
            Type realModelType = modelMetadata.ModelType;

            Type underlyingType = Nullable.GetUnderlyingType(realModelType);
            if (underlyingType != null)
            {
                realModelType = underlyingType;
            }
            return realModelType;
        }

        private static readonly SelectListItem[] SingleEmptyItem = new[] { new SelectListItem { Text = "", Value = "" } };
    }
}

Thanks to http://blogs.msdn.com/b/stuartleeks/archive/2010/05/21/asp-net-mvc-creating-a-dropdownlist-helper-for-enums.aspx for the blog post. Just posting this on gist so i can reuse it.