While fellow late-night host Jimmy Kimmel put his "issues aside" and tweeted a congratulatory message the outgoing Tonight Show host on Thursday, O'Brien joked about Leno's departure on TBS' Conan. The famous redhead, who was forced out of his Tonight Show job to make room for Leno in 2010, said, "The Olympics start airing tonight on NBC. It's very cool. That's right, NBC has the Olympics. It's a big deal. NBC will finally get to show somebody who is OK with passing the torch."
O'Brien, 50, paused for laughter, and added, "I allowed myself one, but it was a good one."
Leno's friendly rival David Letterman refrained from making jokes about the late-night shakeup of 2010 on CBS' The Late Show, saying, "Congratulations on a wonderful run, and I'll tell you something—If I was Jay Leno and I was retiring, you know what I would do? I'd go out and buy myself a car."
Jimmy Fallon, who takes over The Tonight Show on Monday, Feb. 17, paid tribute to his predecessor on Late Night. "To Jay, we say thank you very much. He's been a great guy. We're going to miss him." He then joked, "The ratings have been so good this last week because it's his last week that NBC is going to extend his week—so we're going to have another week of saying goodbye to Jay Leno."
Arsenio Hall, who returned to the late-night arena in 2013, also congratulated Leno on his 22-year run.
"I can't believe he's going. Here's the crazy thing: forget everything you've heard. He's No. 1. and they're getting rid of the No. 1 guy. It shows that the business is really changing. He's the Michael Jordan of late-night. That's like somebody saying, 'Hey, Mike! Put your tongue back in your mouth and get out of here!'" said Hall, whose show was originally on the air from 1989 to 1994. "It's pretty crazy, but we love him. He's the living legend of late-night. Let's give him a big round of applause."
At the end of Thursday's Tonight Show, Leno got emotional. "This has been the greatest 22-years of my life. I am the luckiest guy in the world," he told the audience, tearing up. "It's just been incredible."
(E! and The Tonight Show are both part of the NBCUniversal family.)