Michael Jackson and Sir Paul McCartney's 1983 duet 'Say Say Say' is the King of Pop's most popular track of all time.

According to statistics released by Billboard, the song is more popular than songs including 'Billie Jean' and 'Beat It'.

'Say Say Say' topped the the US chart for six weeks upon its release in 1983, while 'Billie Jean' was number one for seven weeks.

However, Jackson and McCartney's collaboration enjoyed a longer stay inside the top-10.

Other songs in the countdown including Jackson's solo single 'Rock With You' and the Jackson 5 hit 'I'll Be There'.

Meanwhile, Sir Paul McCartney is celebrating his 68th birthday today (June 18).

(by Jason Gregory)