19 songs you forgot were No. 1 hits in the 2000s

As well as peaking at No. 1 on the Billboard Hot 100, Crazy Town's "Butterfly" also made it to the top spot in Austria, Denmark, Germany, Greece, Norway, Poland, Romania, and Switzerland.

Guitarist Kraig "Squirrel" Tyler told HipOnline at the time that he was worried the success of the track would see Crazy Town become a "one-hit wonder" and that they would never "be heard of again."

The band split just two years later.

If somebody asked you what song was Sisqó's only ever No. 1 hit, you'd be forgiven for answering "Thong Song."

It wasn't, however. Instead, it was "Incomplete," the third and final single from his debut album "Unleash the Dragon."

Janet Jackson's "Doesn't Really Matter" spent three weeks at No. 1 after replacing Sisqó's "Incomplete" at the top of the Billboard Hot 100.

The song featured on both Jackson's seventh studio album "All For You" and the soundtrack to the film "Nutty Professor II: The Klumps," in which Jackson starred as the titular character's love interest.

Ja Rule was the rap king of the Billboard Hot 100 in the noughties, scoring three No.1 hits and eight more top 10 hits as either a lead or featured artist.

You probably remember "Always On Time" with Ashanti and "What's Luv?" with Fat Joe, but you may have forgotten Rule's cameo on Jennifer Lopez's "Ain't It Funny," which spent six weeks at No. 1 starting from March 9, 2002.

"Angel" was the followup single to Shaggy's iconic breakthrough hit "It Wasn't Me."

Just like its predecessor, the song made it to the top of the Billboard Hot 100, albeit for only one week.

Santana's "Maria Maria" first made it to the top of the Billboard Hot 100 chart on April 8, 2000, and stayed there for 10 weeks.

Only Destiny's Child's "Independent Women Part I" held the No. 1 spot for longer that year.

In 2017, DJ Khaled sampled the track for his smash hit "Wild Thoughts" with Rihanna and Bryson Tiller.

B2K's first and only No. 1 hit "Bump, Bump, Bump" spent just one week at the top of the Billboard Hot 100 in February 2003.

The group's followup hits "Girlfriend" and "Badaboom" both also charted before they split in 2005.

"I Believe" was the debut single of "American Idol" season three winner Fantasia. In typical "American Idol" style, it's cheesy, cringy, and very, very forgettable.

Though recorded a year prior, "Slow Motion" wasn't released until 2004, after Soulja Slim was shot dead in November 2003.

One of only a handful of posthumous No. 1 hits ever at the time, it was also the first chart-topper for Birdman's label, Cash Money Records.

Quite how D4L's "Laffy Taffy" ever made it to No. 1 is a mystery.

Even D4L's own Fabo hated it.

"I hated the song," he told Complex in 2016. "I swear to God, I hated the song. I could remember Shawty Lo calling home from jail saying, 'Don't put that song out!'"

"We about to start an epidemic with this one," says producer Jermaine Dupri at the start of the video for "Grillz."

He was right. Once worn only by wealthy Etruscan women, grills became all the rage as a result of the St. Louis rapper's ode to dental jewelry.

James Blunt's "You're Beautiful" spent five weeks at No. 1 in the United Kingdom, but just one at the top of the Billboard Hot 100.

It did win an MTV Video Music Award for best male video, however.

MIMS — or "Music Is My Savior" — couldn't save his career from falling off a cliff after he scored a No. 1 hit with "This Is Why I'm Hot" in 2007.

He released just two albums before giving up music entirely to begin working in technology.

"Kiss Kiss" was Chris Brown's second No. 1 on the Billboard Hot 100.

It's best remembered for its music video, in which Brown plays two characters, a nerd and a jock, both of whom are trying to get the girl. The nerd wins, of course.

Leona Lewis enjoyed amazing success after winning the third series of "The X Factor" UK in 2006.

Her second single "Bleeding Love" went to No. 1 in 35 different countries, making it only the second song in history to achieve that feat after Elton John's "Candle in the Wind 1997."

T.I. had released six albums and 16 singles as a lead artist before finally scoring a No. 1 on the Billboard Hot 100 with his 2008 effort "Whatever You Like."

He scored his second No. 1 the following month as he teamed up with Rihanna for "Live Your Life."

"Crack A Bottle" fell victim to being followed at No. 1 by a series of smash hits, meaning it quickly fell into obscurity.

After holding the top spot, it was succeeded by Flo Rida's mammoth hit "Right Round," Lady Gaga's debut hit "Poker Face," and then the biggest song of the year, The Black Eyed Peas' "Boom Boom Pow."

Jay Sean became the first solo artist of South Asian origin and the first urban act from the United Kingdom to top the Billboard Hot 100 with his smash hit "Down."

Featuring Lil Wayne, the track was his only ever No. 1.

"3" was, ironically, Britney Spears' third of five Billboard Hot 100 No. 1 songs, the others being "Baby One More Time," "Womanizer," "Hold It Against Me," and "S&M."

Believe it or not, "Oops! I Did It Again" and "Toxic" — arguably her two most iconic songs — never achieved that feat.

Listen to all the tracks here: