Registering a triple-double is an achievement on its own, especially in today's NBA, where players score at a more efficient rate. Even so, some players have played their hearts out to make sure they stuff the stat sheet as often as possible.Triple-doubles happen when a player registers double digits in any three of the five NBA stat-lines in a single game. Although getting double-digits in points, rebounds, and assists is the most common type of triple-double, few players have achieved triple doubles with other parameters too.Draymond Green is a perfect example of that, as the Golden State Warriors forward registered a triple-double with steals. In a game against the Memphis Grizzlies in 2017, he registered 12 rebounds, ten assists and ten steals.Even as most players have had heroic runs leading to triple-doubles, our focus is on ones that have achieved it on a more regular basis. It will be interesting to know that some players have had full NBA careers without recording a single triple-double. However, Luka Doncic deserves an honorable mentionm as the youngster has registered 36 triple-doubles in only three years.On that note, here are the five players with the most triple-doubles in the 21st century.#5 Nikola Jokic - 57Nikola Jokic (#15) of the Denver NuggetsAmong the 20 players to register multiple triple-doubles in the 21st century, Nikola Jokic is the only center, and he sits at number five. He was selected by the Denver Nuggets in the 2014 NBA Draft with the 41st overall pick, and has since then continued to develop as an all-around player.Jokic, who became the first second-round pick to win an NBA MVP award, registered his first triple-double during his sophomore season in a game against the Milwaukee Bucks. He ended that game with 20 points, 12 rebounds and 11 assists.Nikola Jokic earned the 15th triple-double of his NBA career today, in his 226th game. Only four players in NBA history reached 15 triple-doubles in fewer games: Oscar Robertson (40th game), Magic Johnson (116th), Grant Hill (193th), and Jason Kidd (209th). @EliasSports pic.twitter.com/zS8rg0r8pX— NBA.com/Stats (@nbastats) April 7, 2018So far, the 26-year-old big man has reached the triple-double milestone 57 times in his career. With more NBA action in the coming years, the evolving Serbian has enough time to climb higher up the list. The 2021-22 NBA season will be a great start, as he is expected to lead the team again owing to Jamal Murray's continued absence due to injury.#4 James Harden - 58James Harden (#13) of the Brooklyn NetsJames Harden joined the league in 2009 after he was selected by the Oklahoma City Thunder as the third overall pick in the 2009 NBA draft. Barring his playoff failures, his 12-year NBA player has been incredible, as he has led the league in scoring for three consecutive seasons and was named the MVP in 2018.James Harden is the only player with a 60pt triple-double in NBA historyThe Beard also has the most career 50pt triple-doubles (5) in NBA history pic.twitter.com/9cmS6QVaZd— Pro Sports Outlook (@PSO_Sports) August 27, 2021It took Harden four years to get going in the triple-double department, as his first came in 2013. Although he came close on several occasions, he hit the mark on the second of February in a game against the Charlotte Hornets. He ended that night with 21 points, 11 rebounds and 11 assists.Harden has a chance to move up this list, as the player ranked directly above him is retired.Also Check Out: Latest NBA News, Rumors and Updates