2003年最佳金曲獎

"Best Song of the Year" (年度最佳歌曲) is a common award category in music award shows, but without specifying a particular award show or region, it's challenging to provide an accurate answer. However, I can offer you the winner of the Grammy Award for "Song of the Year" in 2003, which is one of the most prestigious awards in the music industry.

The Grammy Award for "Song of the Year" in 2003 went to "Don't Know Why" by Norah Jones. The song was written by Jesse Harris and was featured on Norah Jones' debut album, "Come Away with Me." Norah Jones also won several other Grammy Awards that year, including Album of the Year and Best New Artist.

If you're referring to a different award show or a specific region, please provide more context so I can give you the correct information.