My implementation of a ActionLink method Font-Awesome-Friendly.

FontAwesomeActionLink

    <!-- language: c# -->
    
    public static class HtmlExtensions
    {
        public static IHtmlString FontAwesomeActionLink(this HtmlHelper htmlHelper, string linkText,
            string actionName, string fontAwesomeClass, object routeValues = null, object htmlAttributes = null)
        {
            return FontAwesomeActionLink(htmlHelper, linkText, actionName, null, fontAwesomeClass, routeValues,
                htmlAttributes);
        }

        public static IHtmlString FontAwesomeActionLink(this HtmlHelper htmlHelper, string linkText,
            string actionName, string controllerName, string fontAwesomeClass, object routeValues = null, object htmlAttributes = null)
        {
            var targetUrl = UrlHelper.GenerateUrl(null, actionName, controllerName, ObjectToDictionary(routeValues), htmlHelper.RouteCollection, htmlHelper.ViewContext.RequestContext, true);
            return new MvcHtmlString(GenerateLink(linkText, targetUrl, fontAwesomeClass, HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes)));
        }

        private static string GenerateLink(string linkText,
            string targetUrl,
            string fontAwesomeClass,
            IDictionary<string, object> htmlAttributes
        )
        {
            var a = new TagBuilder("a");
            
            a.MergeAttributes(htmlAttributes);
            a.MergeAttribute("href", targetUrl);

            var i = new TagBuilder("i");

            i.MergeAttribute("class", "fa " + fontAwesomeClass);
            a.InnerHtml = i.ToString(TagRenderMode.Normal) + " " + linkText;

            return a.ToString(TagRenderMode.Normal);
        }

        public static RouteValueDictionary ObjectToDictionary(object value)
        {
            var dictionary = new RouteValueDictionary();

            if (value != null)
            {
                foreach (PropertyInfo property in value.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance)
                                                           .Where(prop => prop.GetIndexParameters().Length == 0 &&
                                                                          prop.GetMethod != null))
                {
                    dictionary.Add(property.Name, property.GetValue(value));
                }
            }

            return dictionary;
        }
    }