Ron Artest (Metta World Peace) went into the stands and punched a fan. A full brawl broke out. 9 players suspended. Artest got 86 games (rest of season). The ugliest moment in NBA history.
NBA referee Tim Donaghy bet on games he officiated. He went to prison. The NBA insists it was an isolated case. Nobody believes them. Every bad call now gets "Donaghy" references.
LeBron announced he was leaving Cleveland for Miami on live TV. "I'm going to take my talents to South Beach." Cleveland burned his jersey. His owner wrote a Comic Sans letter. The most hated sports moment of the decade.
Clippers owner caught on tape making racist remarks. Banned for life. Forced to sell the team for $2B. Steve Ballmer bought it. Sometimes scandals have happy endings.
MLB, not NBA — but it shook all of sports. The Houston Astros used cameras to steal signs. Won the World Series. Barely punished. "If you ain't cheating, you ain't trying" became a dark joke.