The Forbes Top Ten:1 Manchester United - £1.43bn2 Real Madrid - £1.20bn3= NY Yankees - £1.18bn3= Dallas Cowboys - £1.18bn5 Washington Redskins - £1bn6= LA Dodgers - £895m6= NE Patriots - £895m8 Barcelona - £838m9 New York Giants - £831m10 Arsenal - £825mLONDON – Manchester United have retained their title as the world’s most valuable sports team, according to Forbes.Earlier this month, the club applied to be listed on the New York Stock Exchange as the Glazer family seeks to raise $100 million (£64 million) to reduce a debt level that, the application noted, "could adversely affect our financial health and competitive position”.United were valued at £1.43 billion in the latest Forbes top 50, down from £1.65 billion in the 2011 list, but were still rated 19% more valuable than their closest rivals, Real Madrid.All 32 NFL franchises made the top 50 list, with the Dallas Cowboys, Washington Redskins, New England Patriots and Super Bowl champions New York Giants all securing spots in the top ten.The Forbes top 50 included seven football teams, with Arsenal falling three places to tenth and Barcelona up 18 to eighth.