The two teams were the Seattle SuperSonics and the Chicago Bulls who were the winners.
Boston Celtics with 17 championships.
There are 32 teams.
Lakers & Celtics
Michael Jordan played in six NBA championships and won all six (1991, 1992, 1993, 1996, 1997, 1998).
Los Angeles Lakers and Orlando Magic
1) Boston Celtics - Winners of the 2008 NBA championship, they won 11 NBA championships in 13 seasons between the 1956-57 and 1968-69 seasons. They have won the most championships in the history of the NBA with 17. 2) Los Angeles Lakers - The Lakers have won 14 NBA championships, second most in NBA history. The Lakers have played in 29 NBA championship series, the most of any NBA team. Through the 2008 season, the Lakers have the best franchise winning percentage of any team (2905 wins, 1824 losses, .614 winning percentage). The Celtics and Lakers are by far the most famous teams in the NBA. There are several teams that have had 6 or 8 years stretches where they have been dominant, the Chicago Bulls who won 6 NBA championships in 8 seasons with Michael Jordan and the San Antonio Spurs who currently have won 4 championships in 10 seasons, but no teams have won like the Celtics and Lakers.
Los Angeles Lakers (in 2004)
The Chicago Bulls. They won 6 championships in the years 1991, 1992, 1993, 1996, 1997, 1998.
Michael Jordan won six NBA championships as a member of the Chicago Bulls. 1997-1998, 1996-1997, 1995-1996, 1992-1993, 1991-1992, and 1990-1991
Shawn Bradley has played for three NBA teams. He played for the Dallas Mavericks, the Philadelphia 76ers, and the New Jersey Nets.
Celtics have won 17 championships, and Lakers 16 - the two teams with the most championships. So yes, in many ways they are the most successful franchises in the NBA.