Madonna celebrates 55th birthday

Happy birthday, Madonna! The Queen of Pop turns 55 on Friday, Aug. 16.

Over her three-decade-long career (her debut album was released in 1983), the pop queen has sold more than 300 million records worldwide, amassed a collection of No. 1 singles and gone through many a style evolution. (Who could forget the cone bra?)

Now a mother of four, the original Material Girl is showing no signs of slowing down. Her "MDNA" tour last year was the highest-grossing tour of 2012.

On her Instagram page, Madonna thanked fans for their birthday wishes and asked them to celebrate by donating to Raising Malawi, the charity she co-founded to help end the poverty and hardship endured by Malawi's orphans (Madonna's two youngest children, David and Mercy, were adopted from the African country).

In celebration of the pop star's birthday milestone, we've included a few of her music videos below.

Tell us: What's your favorite Madonna song?