In case you were wondering, WebClient handles GZIP encoded content.

  private static string GetPageMarkup(string uri)
        {
            string pageData = null;
            using (WebClient client = new WebClient())
            {
                pageData = client.DownloadString(uri);
            }
            return pageData;
        }
      

If you want to send a CookieContainer with the GET Request, you have to do smoething special:

      

        class WebClientEx : WebClient
        {
            protected override WebRequest GetWebRequest(Uri address)
            {
                WebRequest request = base.GetWebRequest(address);
                if (request is HttpWebRequest)
                {
                    (request as HttpWebRequest).CookieContainer = PersistentCookies.GetCookieContainerForUrl(address);
                }
                return request;
            }
        }

  
    

        class PersistentCookies
        {
            // to get persistent cookies for TinyPic
            [DllImport("wininet.dll", CharSet=CharSet.Auto , SetLastError=true)] 
            private static extern bool InternetGetCookie (string url, string name, StringBuilder data, ref int dataSize);

  
            private static string RetrieveIECookiesForUrl(string url)
            {
                StringBuilder cookieHeader = new StringBuilder(new String(' ', 256), 256);
                int datasize = cookieHeader.Length;
                if (!InternetGetCookie(url, null, cookieHeader, ref datasize))
                {
                    if (datasize < 0) 
                        return String.Empty;
                    cookieHeader = new StringBuilder(datasize); // resize with new datasize
                    InternetGetCookie(url, null, cookieHeader, ref datasize);
                }
                // result is like this: "KEY=Value; KEY2=what ever"
                return cookieHeader.ToString();
            }

            public static CookieContainer GetCookieContainerForUrl(string url)
            {
                return GetCookieContainerForUrl(new Uri(url));
            }

            public static CookieContainer GetCookieContainerForUrl(Uri url)
            {
                CookieContainer container = new CookieContainer();
                string cookieHeaders = RetrieveIECookiesForUrl(url.AbsoluteUri);
                if (cookieHeaders.Length > 0)
                {
                    try
                    {
                        container.SetCookies(url, cookieHeaders);
                    }
                    catch (CookieException) {}
                }
                return container;
            }
        }

  
        private static string GetPageMarkup(string uri)
        {
            string pageData = null;
            using (WebClientEx client = new WebClientEx())
            {
                pageData = client.DownloadString(uri);
            }
            return pageData;
        }