In celebration of Britney Spears’ 42nd birthday, here are the top 5 most iconic songs highlighting her everlasting impact on the world of music, even after all these years.

Britney Spears (IMDb)

Since catapulting to the forefront of pop culture when she was just a teen in the late ’90s, Britney Spears has earned five No. 1s and 13 top 10s on the Billboard Hot 100 – not to mention selling 34 million albums in the U.S., per MRC Data.

But Britney isn’t just one of the biggest artists of the 20th century. She’s also one of the most defining cultural touchstones of the early 2000s, having symbolized everything from suburban schoolgirl innocence to bold sexual confidence to resilience and hard-fought freedom.

In honor of Britney Spears’ 42nd birthday (Dec. 2), Pinkvilla revisited her extensive catalog of pop classics and came up with our staff picks for Britney Spears 5 most iconic songs.

Toxic (2003)

Britney wanted a new hit song, and back in 2001, she really needed it. Her album Britney did well, but not as well as her first two. Most of the songs from it didn’t do great on the radio. Also, everyone was talking about her breakup with Justin Timberlake, and he seemed to control the narrative with his song and video Cry Me a River. The time when Britney was ruling TRL (Total Request Live) was fading, and her first single from the 2003 album In the Zone, a Madonna collaboration called Me Against the Music, didn’t get much attention.

To prove she was still the queen of pop, Britney needed a big hit. Luckily, she had Toxic. The song starts with intense strings that grab your attention, and they get even more captivating as the song goes on. Then there are guitars, both strong and smooth, adding to the excitement. And, of course, Britney herself sounds more flexible than ever, moving around the song’s many hooks. She takes control in the five-star chorus, singing, “I’m ADDICTED to you / don’t you know that you’re toxic?” It’s proof to Britney’s pop greatness.

Gimme More (2007)

The song starts with the famous line, It’s Britney, bitch, and ends with the producer, Danja, proudly talking about the great song that just played. In between, Gimme More lives up to the confidence it expresses. It’s like Britney is energetically changing her music style. When you don’t think about the tough stuff Britney was going through at that time, the song still sounds cool and modern today. Despite all the challenges in her life, Britney found a way to make music that suited her—mixing flexible electro-pop with bold sound experiments. By cleverly using a certain strong word, she showed she was leaving her younger image behind and embracing a more grown-up, confident attitude.

Oops! … I Did It Again (2000)

Oops!… I Did It Again was the first song from Britney’s second album. Its main goal was to keep the success going that Britney started with her first album, …Baby One More Time, which had many hit songs. Max Martin and Rami Yacoub, the music makers, created another catchy and fun song. Britney’s playful performance added to the charm of the song. The album with the same name as the song sold a massive 1.39 million copies in its first week, showing that Britney’s popularity was still growing, and she made it look easy.

(You Drive Me) Crazy (1999)

As Britney’s third single (and the second track on her debut album), (You Drive Me) Crazy made it clear that …Baby was just the opening salvo — this Louisiana teen was going into the new millennium with an imposing Swedish pop arsenal behind her and taking no prisoners. While Britney keeps it cool on the verses, letting her vocal fry and melisma suggest the extent of her infatuation, she lets it all out on the roaring chorus, where Spears and Max Martin summon the intensity of a Bon Jovi anthem and fine-tune it for teen-catering clubs (which was, in fact, the setting of the Stop! Remix video, a tie-in to a Melissa Joan Hart/Adrian Grenier romcom). If it’s not the only song in existence where a clanging cowbell is used to evoke the pounding rush of teenage hormones, well, then it’s certainly the best.

… Baby One More Time (1998)

At the end of the 1990s, Britney Spears released her first song, …Baby One More Time, which nailed the style of teen pop made famous by NSYNC and Backstreet Boys. The song not only made Britney a huge star but also showed that a girl from rural Louisiana could be just as captivating as all the boys in boy bands combined, especially in one music video. The iconic image of Britney in a schoolgirl outfit with pigtails and knee-high socks became a symbol of Y2K Pop Culture.

The song itself is like a snapshot of the American high school experience, a time when the biggest worries were getting your crush to like you and trying to prove you’re grown-up, even though everyone knows you’re not. Even though Britney was a teenager herself when the song came out, her alluring voice and undeniable charm immediately made her a powerful and unforgettable figure.