The Departed is an amazing film -- one that I would consider Scorcese's best. I've seen Infernal Affairs, and while it was an interesting idea, it had a lot of problems. The Departed feels like the realization of what Infernal Affairs could and should have been. The cast is amazing, and Leonardo DiCaprio's performance is especially admirable. The Departed is one of the best crime thrillers in years, and I'd highly recommend it.