The Los Angeles Lakers won five championships in nine years.
Los Angeles Lakers . Initially a member of the NBL , the Lakers won the 1948 NBL championship before joining the rival Basketball Association of America and winning five of the next six BAA and NBA championships in Minneapolis after the NBA formed in 1949 . The 1980s Lakers were nicknamed `` Showtime '' due to their Magic Johnson-led fast break-offense , and won five championships in a 9-year span , including their first ever Finals championship against the Celtics in 1985 .