John Patrick McEnroe was the American tennis player who won 7 grand slams in the 1970s and 1980s.
er - women do not play men's tennis
Don Budg was the first player who won all the 4 Grand Slams.
17 grand slams wow
Roger Federer: 16 grand slams
Maureen Connolly of USA won all the 4 Grand Slams in a year in 1953.
Margaret Court Smith, 24 Slams. She also won 38 doubles titles in grand slams, 19 women's doubles and 19 mixed doubles
Serena Williams is ranked number one, and is the player to have won the most grand slams on the WTA tour at the moment. So, in my opinion, she is the best. But, Steffi Graf (a retired player) has won many more grand slams than Serena.