"Alexis m'attend" (Alexis is waiting for me), performed by Philippe Lafontaine
At first, this song seems to be sad and laconic (even in french when you understand the lyrics) but for me it's an optimist song because in spite of the challenges, in spite of the ugliest things in the world and the sadest events in your life, when you're sure about your love feeling for someone, you're able to overcome the obstacles...