There's no doubt in my mind that the greatest dynasty of all time is the 1957-1969 Boston Celtics. Over 13 seasons, this team won 11 NBA championships, with eight of them coming consecutively from 1959-1966. While their roster consisted of virtually nothing but future Hall of Famers, it could confidently be argued that none of them would have been as great as they were without the leadership of Red Auerbach (Boston Celtics coach from 1950-1967), one of the all-time winningest coaches in the NBA's history. Stressing teamwork over individual accomplishment, a league-leading scorer never numbered among the Celtics that Auerbach led to so many championships. In lieu of a true superstar, Auerbach stressed play that heavily relied on fast breaks and a reserve player that came off the bench more than others (this is what we refer to today as a the "sixth man").
While there have been other NBA dynasties, all of them depended on a high-profile player or two instead of almost wholly on a then-pioneering style of coaching. While dominant talent in the NBA is undoubtedly more exciting to watch, success built less on exceptional talent and more on ingenious strategy is always more impressive. Ultimately, this is what leads me to believe that no other sports dynasty is as great as that of the 1957-1969 Celtics.