Róméó és Júlia
(Hungarian production of the French musical Roméo et Juliette, de la haine à l'amour. It premiered on January 23rd, 2004 so it turned 20 earlier this year.)
Already DM'd this to Hawk, but I'll post this here as well. My submission revolves around the series of Vocaloid songs, Evillious Chronicles, particularly the Story of Evil part of it. If you've ever listened to Daughter of Evil or Servant of Evil, this is where those songs are from!