Not sure I'd go greatest but I really like how Rock of Ages worked the songs into the story, paired songs together and I was pretty impressed that Tom Cruise did his own vocals (not that he was part curly wonderful but it is gutsy).
Thread is probably losing momentum, but I want to add Jon Brion's score to Synecdoche, New York. (A good Philip Seymour Hoffman one). Anyway, a great original score.
