The Dallas Cowboys are the kings of the professional football world -- when it comes to retail, anyway. Led by wide receiver Dez Bryant, the Cowboys owned the top three spots on the NFL Players Association's Top 50 player sales list for the year's first quarter (March 1-May 31). Bryant -- who was joined by quarterback Tony Romo and rookie running back Ezekiel Elliott to round out that top three -- is the first non-quarterback to top the quarterly sales rankings, the NFLPA announced.[Click here to view the full Top 50 player sales list.]The NFLPA first began compiling the list, which is based on total sales of all officially-licensed NFL player merchandise, in 2013.