The music trivia site This Day in Music has a nice little service that tells you what song was #1 on the charts the day you were born. While I'm thankfully too old to have been born under Madonna - Lucky Star, my actual birth-tunes (for 27.05.1972) are pretty respectable:
US: The Chi-Lites – Oh Girl
UK: T. Rex – Metal Guru
They don't have a Canadian chart, and those archives proved a little hard to find. The Canadian #1 for that week was a bit surprising:
The Royal Scots Dragoon Guards – Amazing Grace
Scott... Scots Guards, whoa.