Conan O’Brien is shown during the filming of “Conan O’Brien Can’t Stop” a film chronicling O’Brien’s 32-city concert tour after he left NBC in early 2010. (Rodman Flender • A Pariah Production/The Minnesota Star Tribune)

1993: After a stint on the "Saturday Night Live" writing staff, O'Brien moved to "The Simpsons," where he penned several classic episodes, including "Marge vs. the Monorail," packed with hilarious references to "The Music Man," "Star Trek" and "Silence of the Lambs." Many critics consider it to be one of the show's finest episodes.

1993: Although unknown outside of writers' rooms, O'Brien is anointed by producer Lorne Michaels to take over "Late Night." The show premiered with the eternally optimistic host cheerfully greeting everyone from doormen to Tom Brokaw as they remind him that he has big shoes to fill. The segment ends with O'Brien preparing to hang himself.

1994: O'Brien was getting trounced in the ratings, when he got an unexpected lifeline: David Letterman volunteered to appear as a guest. At one point Letterman asked his replacement how he had gotten the gig. "There was a theme-writing contest," O'Brien said. "I came in fourth." At that moment, the baton had been passed.

1996: A studio fire forced the show to be broadcast from outside Rockefeller Plaza, inspiring a great bit in which O'Brien and sidekick Andy Richter go chair shopping for leadoff guest Samuel L. Jackson.

1997: Letterman has called Norm Macdonald one of the funniest people on the planet. But the former "SNL" anchor had his greatest talk-show moment with O'Brien. During an O'Brien interview with Courtney Thorne-Smith, Macdonald kept butting in from the couch to make fun of her latest co-star, Carrot Top. O'Brien came down with a serious case of the giggles.

2001: "Late Night" leaned heavily on "SNL" veterans, including Will Ferrell. In one of his greatest appearances, Ferrell impersonated Robert Goulet as a washed-up drunk who mistook O'Brien for Johnny Carson and practically burped his way through the interview. It could be considered another mean-spirited bit, but it showed how O'Brien gave his guests room to do more than promote their latest project.

2002: Of all the recurring characters, no one made more of a splash than Triumph the Insult Comic Dog. One could argue as to the puppet's most outrageous moment, but it's hard to beat the time he ripped into "Star Wars" fans lined up to watch the premiere of "Attack of the Clones."

2008: No one handled the writers strike with more creativity than O'Brien. In his first week back, he spun his wedding ring on the desk, trying to beat his record of 41 seconds, sang "Blue Moon of Kentucky" with the band, and climbed up the studio catwalk with a camera.

2010: Less than a year after getting "The Tonight Show," O'Brien walked away rather than accept a later time slot. He spent his last weeks skewering his bosses, insisting that he was going to bankrupt NBC. The final episode featured a skeleton from the Smithsonian spraying a Picasso painting with caviar, a sketch O'Brien claimed cost the network $65 million. He later explained that he was joking.

2010: After a fair amount of skulking, O'Brien hit the road. "The Legally Prohibited From Being Funny on Television Tour" was at its best when it strayed from the established set and zeroed in on jokes with local ties. During his Minneapolis stop, the concert neatly dropped in references to Jucy Lucys, WCCO's Amelia Santaniello, skyways and Leeann Chin's before the host jammed with surprise guest Brian Setzer on "Rock This Town." The film "Conan O'Brien Can't Stop" documents this period.

2011: Doing stand-up on "Conan" wasn't as big a deal as getting a shot on Johnny Carson's "Tonight Show." But it didn't hurt. O'Brien's platforms gave big boosts to the careers of Patton Oswalt, Sarah Silverman and Dave Chappelle. In perhaps the greatest breakout moment, Tig Notaro used most of her set time to push a stool across the stage. It was a bit that would have left Carson scratching his head. O'Brien ate it up.

2018: In 2015, O'Brien started churning out international specials in a series that would eventually be called "Conan Without Borders." Of all the journeys, none packed in more laughs than his visit to Italy with deadpan producer Jordan Schlansky, who insists he knows everything about the country. Watching O'Brien take him down is bellissimo.

Njustin@startribune.com

612-673-7431 • Twitter: @nealjustin

Above, O’Brien interviewed frequent guest Will Ferrell in 2009. At top, a scene from the film “Conan O’Brien Can’t Stop,” which chronicled his 32-city tour in 2010. (NBC/ Associated Press photos/The Minnesota Star Tribune)

O’Brien in 1993. (The Minnesota Star Tribune)