'TRL' launched 25 years ago. Here are 10 memorable moments from the beloved MTV countdown show.

Carson Daly, fittingly, was quick to recognize the importance of the day:

"25 yrs ago today, before Instagram, TikTok & Facebook there was TRL," Daly wrote on Instagram. "The 1st truly interactive, fan driven show on tv. It was my home for some of the best years of my life. I had the privilege to introduce so much to so many. Music, movies, celebrities, world events & more. All Live, everyday. I'm so grateful for that time & all of you who allowed me (and my T-Mobile SideKick) to be apart of your life. I hope this finds you happy & healthy 25 yrs later. Hey, I wonder if that Backstreet Boys fangirl who yelled at me is still mad? Lol…Good times."

Part concert, part talk show and part countdown of the day's top videos as voted on by fans, the first iteration of TRL — officially called Total Request Live — ran until 2008. Most of it hosted by Daly, a former radio personality at legendary Los Angeles station KROQ, who has continued to work in TV, on The Voice and Today. TRL also boosted the careers of those who stepped into the role after he had left by 2003, people like La La Anthony, Hilarie Burton and Vanessa Lachey.

Viewers could regularly expect to see stars such as Brandy, Usher, Eve, Snoop Dog, No Doubt, Jennifer Lopez and Jessica Simpson. Celebs in any kind of media, whether movies, TV or music, usually made a TRL stop before a new release.

In honor of the show's format, here's a countdown of TRL's most memorable moments:

10. Tom Green's "Lonely Swedish (The Bum Bum Song)" takes the top spot

The Canadian comedian's MTV show, which was part sketches, part pranks, part talk and all ridiculous (and pretty funny) — debuted in the U.S. in early 1999. He quickly riffed on a line from one of the episodes — "My bum is on the rail" — to create an entire song and music video that, for whatever reason, resonated with TRL viewers. When he asked them to vote for it, they did, until he voluntarily retired it, at least that's how it seemed. The future Mr. Drew Barrymore said years later on The Joe Rogan Experience that he was pressured to do so by MTV execs.

9. Eminem hosts "Em TV"

When the rapper hosted the show in May 2000, he did away with the traditional countdown and chose his own playlist. He also slammed the videos of Britney Spears, NSync and the Backstreet Boys.

8. Beyoncé and Jay-Z become a duet

The artists joined forces in 2002 — in matching denim, as the era required — to perform their first track together, "'03 Bonnie & Clyde." They had not yet confirmed that they were together, but the Destiny's Child star said the two had "met a long time ago."

7. NSync promotes 'Tearin' Up My Heart' in '90s fashion

TRL hadn't been on the air long when Justin Timberlake, Lance Bass, JC Chasez, Joey Fatone and Chris Kirkpatrick made their way there to perform their second single. They drove the girls in the audience crazy with their dance moves and their super '90s fashion, exemplified with Timberlake's bleached 'do, Kirkpatrick's overalls — and just the whole thing.

6. Diddy (then P. Diddy) runs on the treadmill for an hour

In October 2003, Sean "Diddy" Combs — then known as P. Diddy — took to a treadmill ahead of his run in the New York City Marathon for, as he put it, the kids of New York City. As he looked like a true athlete (in style, of course), none other than Britney Spears was there to ask how he was doing and wipe his sweat.

5. Christina Aguilera performs 'Dirrty' for the 1st time

Aguilera was part of the pop invasion of the late '90s, but she set herself apart in 2002 with the release of her raunchy video for "Dirrty." And the "What a Girl Wants" singer debuted this new style — where else — but on a TRL special to celebrate the release of her album Stripped.

4. Britney Spears is introduced to the world

The Louisiana native premiered the music video for her very first single, "...Baby One More Time," on TRL-. The clip, which featured her in a schoolgirl outfit, dancing through the halls of a school, was hugely popular and helped propel her to the status of icon. MTV's cute footage of Spears talking to Daly reveals she did her own stunts in the video, thanks to her gymnastics training.

3. Destiny's Child says goodbye

With videos like "Survivor" and "Say My Name," the combo of Beyoncé, Kelly Rowland and Michelle Williams had a history at TRL. in 2005, they made what was (at the time) their last appearance as a group on the show and answered questions from fans.

2. Mariah Carey has an on-air 'therapy session'

The TRL favorite's July 19, 2001 appearance on the show appeared to be a total surprise to Daly. What's more, Carey, who was pushing an ice cream cart, seemed out of it. "Sometimes you might just go a bit crazy" without ice cream, she said. Daly declared the show the "most bizarre" he had ever hosted. The songstress told him, "You are my therapy session right now, Carson. Every now and then, somebody needs a little therapy, and today is that day for me." While Carey's publicist said soon after that Carey had had an "emotional and physical breakdown," and the star checked into a rehabilitation facility days later, Carey herself later said she had simply been overworked. Glitter, the movie in which she starred and did music for, was weeks away from release. She said the incident was "A. Stunt. Gone. Awry."

1. The Backstreet Boys shut down Times Square

When BSB appeared on a TRL special ahead of releasing their 1999 album Millennium, their fans overran Times Square, and the bustling district had to be shut down. "That was an amazing time in our lives," Kevin Richards told Entertainment Tonight in May 2019. The "I Want It That Way" singers' "Shape of My Heart" holds the record for video with the most days in the No. 1 spot. The Boy Band Era was so on.