The infamous trade that dealt him from the Edmonton Oilers to the Los Angeles Kings on Aug. 9, 1988, sent shock waves throughout Canada and the United States, triggered death threats against Oilers owner Peter Pocklington, a backlash against Gretzky and his new wife, and forever changed the NHL.
It just wasn't funny at the time.
The trade and its repercussions are the subject of the documentary "Kings Ransom" that will be broadcast Tuesday at 8 p.m. EDT on ESPN.
It launches the cable network's "30 for 30" series featuring 30 one-hour films from such directors as Barry Levinson, Ron Shelton, Spike Jonze, John Singleton and Ice Cube who examine the issues and personalities in sports from ESPN's debut in 1979 to the present.
Peter Berg, a longtime friend of Gretzky's, directed the film that includes interviews with The Great One, Pocklington, former Kings owner Bruce McNall, wife Janet Gretzky and father Walter Gretzky.
"It really brought a tear to my eye watching this," Pocklington said after a recent screening in Beverly Hills, where he reunited with Gretzky and McNall.
The three men have known tough times in the 21 years since they were the talk of the sports world.
The 65-year-old Pocklington was arrested in March and charged with bankruptcy fraud. McNall, 59, served 70 months in prison for bank fraud, wire fraud and conspiracy. Gretzky, 48, resigned last month as coach of the Phoenix Coyotes, who are in bankruptcy court and seeking a new owner.
"We're all great friends now," Gretzky told the audience after the screening at the Paley Center for Media. "We kind of giggle about it a little bit."
The trade so upset Canadians that one elected official demanded the government block it, Pocklington was burned in effigy, Gretzky was called a traitor by some of his countrymen for leaving, and Janet Gretzky was branded hockey's Yoko Ono.
"If I had to do it all over again, I would tell Peter again, 'Trade me,'" Gretzky told the crowd.
At the time, though, he felt a mixture of emotions about being traded for $15 million in cash and a handful of players and draft picks to one of the league's worst teams. Gretzky had just led the Oilers to their fourth Stanley Cup.
"I was probably more mad at Peter than I was at anybody in the world," he said. "Now that I got into the management side of things and into coaching, I understood where he came from."
During the screening, Gretzky and his wife laughed at old pictures of themselves while their youngest son, 9-year-old Tristan, leaned over to whisper comments in his dad's ear.
The film opens with Gretzky, in a suit, tie and polished black shoes, walking into the empty Forum in Inglewood, where he starred for the Kings from 1988-96, when he was traded to St. Louis.
The Kings have never won a Stanley Cup, losing to Montreal in the 1993 finals. McNall was forced to sell a majority stake in the club the following year.
During a golf course conversation, Gretzky tells Berg he still feels bad knowing the Oilers might have won four more Stanley Cups if he had stayed.
Gretzky single-handedly turned Los Angeles into a hockey town, with the Forum selling out and celebrities clamoring for tickets. President Ronald Reagan even attended a game to see No. 99.
Gretzky's popularity led to the NHL adding franchises in Anaheim, San Jose, Phoenix, Florida and North Carolina.
"It was one of the greatest trades ever done and hopefully the fans will get over it one of these years," Pocklington says in the film.
Los Angeles Lakers owner Jerry Buss, who then owned the Kings, first offered Pocklington $15 million for Gretzky in 1985. Pocklington demurred, believing it wasn't the right time.
But three years later, Pocklington wanted Gretzky to renegotiate with a year remaining on his contract. Gretzky refused, setting the stage for hat became known simply as "The Trade."
"I knew I would get nothing for him in the free market because I couldn't bid what others would and that's how the deal got done," Pocklington told the audience. "If I hadn't done what I'd done, we wouldn't have won another Stanley Cup. It was the right thing for hockey and the right thing for the Gretzky family."
When Oilers coach Glen Sather realized the rumors about Gretzky being traded were true, he boiled over. But he was powerless to stop it.
Sather, who is interviewed in the film, posted $1 million bail for Pocklington to get out of jail after his arrest in March.
In the late '80s, player salaries were on the rise and Gretzky's trade was credited with boosting them even higher.
"If I was an owner now, I'd sell out or move to Hamilton," Pocklington said, referring to the Ontario city where one unsuccessful bidder for the Coyotes proposed moving the team. "Economically, it's a struggle. It's easy in Canada; it's the national sport."
McNall remains a fan of the Kings, who have never followed up on the success and popularity they enjoyed during Gretzky's tenure.
"That's the problem with the league today. There is no Wayne Gretzky," he told the audience. "If Sidney Crosby walked in this room, who would know him? In the NBA, every team has a star."
Back in '88, hockey history nearly took a different turn.
When Pocklington told Gretzky he could go wherever he wanted, No. 99 said he would go only to Detroit or Los Angeles, where he lived with Janet, then an actress.
"Janet was always my biggest backer and my biggest fan," he told the crowd.
Later, Gretzky told Pocklington he wanted to go only to LA.
Then the Great One revealed something he said he had never before shared publicly.
"My wife told me, just so the record is straight, 'You should go play in Detroit _ it's a hockey city,'" he said.