We’ve reached the year 2009 in our countdown and the songs seem to be getting only hotter…

Boom Boom Pow and I Gotta Feeling

Black Eyed Peas

Boom Boom Pow topped the Billboard Hot 100, making it the group’s first US number one single. It is the second longest running single to stay atop the Hot 100 in 2009, beaten only by the group’s I Gotta Feeling, the second single from their album, which held the top spot for 14 consecutive weeks. This made the group one of 11 artistes who have occupied the top two positions of the Billboard Hot 100 at the same time.

Knock You Down

Keri Hilson featuring Kanye West & Ne-Yo

Keri Hilson stormed onto the scene as a solo artiste with good hits, but it wasn’t until she released Knock You Down that she got the breakthrough she needed. It was Hilson’s highest charting single, peaking at number three on the Billboard Hot 100. It was a success in the United States also, topping the Hot R&B/Hip-Hop Songs, and reaching number three on the Pop Songs chart.

Best I Ever Had

Drake

Based on the popularity Drake garnered from Best I Ever Had, he decided to release the mixtape So Far Gone as an EP, available for purchase. The track peaked at number two on the Billboard Hot 100 in the US for four weeks making Drake the third Canadian rapper to have a song chart on the Hot 100. The single rose to number one on the Hot R&B/Hip-Hop Songs due to heavy airplay and downloads.

You Belong With Me

Taylor Swift

The third single from Swift’s second studio album — Fearless — You Belong With Me became Swift’s highest-charting effort, surpassing her previous best-charting effort Love Story, which peaked at number four. Driven by non-country radio airplay, the track established the largest crossover radio audience since Faith Hill’s Breathe. You Belong With Me peaked at number two on the Billboard Hot 100.

Waking Up In Vegas

Katy Perry

Taken as the final single off her second studio album — One of the Boys — Waking Up In Vegas was also co-produced by Perry. The track peaked at number nine on the Billboard Hot 100, making it Perry’s third single to reach the top 10. Waking Up In Vegas also went on to become Perry’s second number one hit on Mainstream Top 40. The single also helped the album to return to the top 50 of the Billboard 200 albums chart.

I Know You Want Me (Calle Ocho)

Pitbull

I Know You Want Me is Pitbull’s first single to be successful internationally. The track peaked at number two on the Billboard Hot 100 in the US, which made it Pitbull’s most successful single until Give Me Everything hit number one. It also reached number one on French charts and number four on Mainstream Top 40 radio.