16 grand slams and counting as of 2012. Federer plays the game with grace and efficiency that's unmatched. Federer was #1 for almost six years between 2004 and 2010 and is one of the few that has accomplished a career grand slam.

Pete Sampras was meant to be the champion from an early age. His passion for the game was unquestionable even while staying cool on court. Had the most slams until Federer passed him. While he's known for his deadly serve, I love his jump up in the air overhead smashes!

Martina's longevity says it all. She loves the game and all the versions of it - singles, doubles, and mixed. She's my favorite all-time WTA player!

Nicknamed the "superbrat", McEnroe was the number one player in the 80's. We all loved to watch him play the game - waiting for him to blow up on the umpire and the linesmen. His game and mannerisms were in stark contrast to Bjorn Borg, his #1 nemesis. McEnroe has seven grand slams between Wimbledon and US Open, but never won French or Australian.

Nickname "Ice Man", Borg won 11 grand slam titles between 1974 and 1981. Borg won six French open title and 5 (consecutive) Wimbledon titles. Americans John McEnroe and Jimmy Connors were his primary foes.

Nicknamed the "Rocket", Rod Laver was an Australian player that won the grand slam (all four majors in one year) twice! He was the number one player for seven consecutive years from 1964 - 1970!

Sure, he only won six slams, but Becker stormed into the scene and took Wimbledon at just 17 years of age, unseeded! His serve and diving volleys games was fun to watch and showed off his athletic capabilities.

Steffi won 22 Grand Slam singles titles, second only to Margret Court. In 1988 she won the Golden slam - all four majors plus the Olympics. Graf was the #1 tennis player for a total of 377 weeks between 1987 through 1997.

Would not have made this list with his first stint on the tour between 1986 and 1993 with his "I am bigger than the game" image. "The Punisher" then shed his bad boy image and came back as the hardest working pro in the tour. Agassi won eight Gram Slam titles and an Olympic gold.