Is User-Agent mobile, desktop or maybe TV?

When we design new layout, we need to find out what kind of users are using our website.

The easies way is to parse User Agent string, but it isn't easy.
Just look on following links:

After few tries I ended with last link, which gives me enough result approximation :)

    public static string GetDeviceType(string ua)
    {
        string ret = "";
        // Check if user agent is a smart TV - http://goo.gl/FocDk
        if (Regex.IsMatch(ua, @"GoogleTV|SmartTV|Internet.TV|NetCast|NETTV|AppleTV|boxee|Kylo|Roku|DLNADOC|CE\-HTML", RegexOptions.IgnoreCase))
        {
            ret = "tv";
        }
        // Check if user agent is a TV Based Gaming Console
        else if (Regex.IsMatch(ua, "Xbox|PLAYSTATION.3|Wii", RegexOptions.IgnoreCase))
        {
            ret = "tv";
        }
        // Check if user agent is a Tablet
        else if ((Regex.IsMatch(ua, "iP(a|ro)d", RegexOptions.IgnoreCase) || (Regex.IsMatch(ua, "tablet", RegexOptions.IgnoreCase)) && (!Regex.IsMatch(ua, "RX-34", RegexOptions.IgnoreCase)) || (Regex.IsMatch(ua, "FOLIO", RegexOptions.IgnoreCase))))
        {
            ret = "tablet";
        }
        // Check if user agent is an Android Tablet
        else if ((Regex.IsMatch(ua, "Linux", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, "Android", RegexOptions.IgnoreCase)) && (!Regex.IsMatch(ua, "Fennec|mobi|HTC.Magic|HTCX06HT|Nexus.One|SC-02B|fone.945", RegexOptions.IgnoreCase)))
        {
            ret = "tablet";
        }
        // Check if user agent is a Kindle or Kindle Fire
        else if ((Regex.IsMatch(ua, "Kindle", RegexOptions.IgnoreCase)) || (Regex.IsMatch(ua, "Mac.OS", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, "Silk", RegexOptions.IgnoreCase)))
        {
            ret = "tablet";
        }
        // Check if user agent is a pre Android 3.0 Tablet
        else if ((Regex.IsMatch(ua, @"GT-P10|SC-01C|SHW-M180S|SGH-T849|SCH-I800|SHW-M180L|SPH-P100|SGH-I987|zt180|HTC(.Flyer|\\_Flyer)|Sprint.ATP51|ViewPad7|pandigital(sprnova|nova)|Ideos.S7|Dell.Streak.7|Advent.Vega|A101IT|A70BHT|MID7015|Next2|nook", RegexOptions.IgnoreCase)) || (Regex.IsMatch(ua, "MB511", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, "RUTEM", RegexOptions.IgnoreCase)))
        {
            ret = "tablet";
        }
        // Check if user agent is unique Mobile User Agent
        else if ((Regex.IsMatch(ua, "BOLT|Fennec|Iris|Maemo|Minimo|Mobi|mowser|NetFront|Novarra|Prism|RX-34|Skyfire|Tear|XV6875|XV6975|Google.Wireless.Transcoder", RegexOptions.IgnoreCase)))
        {
            ret = "mobile";
        }
        // Check if user agent is an odd Opera User Agent - http://goo.gl/nK90K
        else if ((Regex.IsMatch(ua, "Opera", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, "Windows.NT.5", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, @"HTC|Xda|Mini|Vario|SAMSUNG\-GT\-i8000|SAMSUNG\-SGH\-i9", RegexOptions.IgnoreCase)))
        {
            ret = "mobile";
        }
        // Check if user agent is Windows Desktop
        else if ((Regex.IsMatch(ua, "Windows.(NT|XP|ME|9)")) && (!Regex.IsMatch(ua, "Phone", RegexOptions.IgnoreCase)) || (Regex.IsMatch(ua, "Win(9|.9|NT)", RegexOptions.IgnoreCase)))
        {
            ret = "desktop";
        }
        // Check if agent is Mac Desktop
        else if ((Regex.IsMatch(ua, "Macintosh|PowerPC", RegexOptions.IgnoreCase)) && (!Regex.IsMatch(ua, "Silk", RegexOptions.IgnoreCase)))
        {
            ret = "desktop";
        }
        // Check if user agent is a Linux Desktop
        else if ((Regex.IsMatch(ua, "Linux", RegexOptions.IgnoreCase)) && (Regex.IsMatch(ua, "X11", RegexOptions.IgnoreCase)))
        {
            ret = "desktop";
        }
        // Check if user agent is a Solaris, SunOS, BSD Desktop
        else if ((Regex.IsMatch(ua, "Solaris|SunOS|BSD", RegexOptions.IgnoreCase)))
        {
            ret = "desktop";
        }
        // Check if user agent is a Desktop BOT/Crawler/Spider
        else if ((Regex.IsMatch(ua, "Bot|Crawler|Spider|Yahoo|ia_archiver|Covario-IDS|findlinks|DataparkSearch|larbin|Mediapartners-Google|NG-Search|Snappy|Teoma|Jeeves|TinEye", RegexOptions.IgnoreCase)) && (!Regex.IsMatch(ua, "Mobile", RegexOptions.IgnoreCase)))
        {
            ret = "desktop";
        }
        // Otherwise assume it is a Mobile Device
        else
        {
            ret = "mobile";
        }
        return ret;
    }