2. Pete Sampras - In his career, Sampras won 14 Grand Slams including seven Wimbledon, five U.S. Open, and two Australian Open titles. Sampras held the world No. 1 ranking for a record 286 weeks. His serve was one of the best the game has ever seen, and his calm and collected demeanor allowed him to dominate for years. His fierce rivalries with Andre Agassi and Patrick Rafter thrilled tennis fans. Despite all his accomplishments, he was never able to win a French Open title or reach the final of the tournament.