Dynasties in sports are rare because competition at the highest level is so incredibly tough. It's what makes teams like the New England Patriots of the past two decades stand out.
And the 1990s Bulls, led by Michael Jordan, Scottie Pippen and Phil Jackson are arguably the best.
They won six championships in eight years, a pair of three-peats. Had Michael Jordan not retired, it could've been eight straight. Or if the Bulls stayed together after 1998, they could've added another one in a lockout shortened 1998-99 season.
But alas, those Bulls teams were remarkable.