...is for Papaoutai.
I shouldn't think there's a single person in the French-speaking world (and even some non-French speaking countries, like Germany) that hasn't heard this song at least once.
It's by the Belgian-Rwandan singer, Stromae (which is maestro in French slang) and is a song about fatherhood and growing up without a father (the title is a phonetic representation of "Papa, où t'es ?", which means "Daddy, where are you?").
It's been a huge success, the video (which is excellent, I must say) has been seen more than 140 million times (yes, you read that right, 140 million!) and it's one of those songs that you hear and then have going round your head for days.
Go on, listen to it!