Serena Williams is one of the highest-paid tennis players of all time, men or women

The grand slams of tennis have come a long ways and now offer the same prize money for the men and women. The same cannot be said of lesser tournaments were there is still a huge pay disparity. Despite this, Serena Williams is still one of the four highest-paid tennis players of all time, rivaled only by the Big 3 in men's tennis, Roger Federer, Novak Djokovic, and Rafael Nadal. Williams will almost certainly pass Nadal this week at the U.S. Open. Williams has been so dominant on the woman's to...