Sweeney Todd: The Demon Barber of Fleet Street (Johnny Depp, Helena Bonham Carter). The only musical movie I know of that's rated R for blood and gore (though, most of it is very, very fake!). It is very dark, morbid almost. The music is pretty epic, with a sinister feel. Yes, the main character is a murderer. (I didn't know Johnny could sing!) As twisted as the whole story is, the message of the musical is simple: Revenge will blind you. I love it, but obviously, it's not for kids!