Just saw the Departed again. Second viewing. A few comments.
1. The Two Leads. Damon does a decent job but his character is underdeveloped. You're not really sure what he is thinking and his motivations, especially at the end are not entirely clear. The bedroom scene where he talks about making a fresh start would have been a great opportunity to really flesh out his character. Never happened. DiCaprio is amazing. He should have been nominated for best actor for this role. Great performance throughout. You really liked him and could sense that he was in too deep. Feel so bad at the end when he gets shot. Still upsetting.
2. The Rest. Nicholson is both very good and very bad. His mannerisms and overacting are annoying. He is great in the beginning. Starts to lose it a bit as the movie goes on. Overall though his character is believable. The girl doesn't do much but serves a purpose, and wow what a slamming bod! Sheen, Baldwin, and Wahlberg are good as well. Of the three, Baldwin makes the most of his role. Sheen was the least memorable. Wahlberg would have been better if he did not play the tough guy in every scene. It is odd that he does this and makes his character very one dimensional. So much so, that the ending seems a bit out of place. The guys in the gang were decent as well. The one with the thick Irish accent was pretty funny.
3. The Story. Scorsese to start the movie does a great job laying out the characters and their histories (giving you brief little snapshots of each). He gives you a lot of information quickly, but it is well done and not confusing. It allows him to start telling the story after the first 15 minutes. The main story, the lives the characters lead and their interactions, is very good. You learn a little bit about everyone. And of course the emphasis is on the double lives led by the two leads. The move is pretty long - and the passage of time in between scenes is hard to figure out - but the pace and action is quick enough to keep you interested. However, the ending is not quite satisfying (although I'm not sure I can think of a better one) and there is a lot hinted at yet unresolved.
-- What does Nicholson give Damon's character when he graduates from the Academy? It is something impressive, we can tell from Damon's reaction, but what it is, I don't know. I saw no reference to it in the movie. My best guess is that the contents of the box were not important and the scene was to just show that Jack was a surrogate father to Damon's character. Parents always give their children a nice gift when they graduate.
-- Who is the father and what did she have to tell DiCaprio? These two are linked. I tend to feel that DiCaprio was the father (there is enough hinted at to suggest this) and that this is what she had to tell him. Also explains why she was so upset at the funeral and had no comment to Damon about the baby.
-- What is in the envelope? It had to be information outlining Damon as the rat and revealing the existence and whereabouts of the tapes to prove it. It must have also said to give this information to Wahlberg's character, which explains the ending. DiCaprio figured that if he could not expose Damon then hopefully Wahlberg - the only person on the force he trusted - could. He doesn't know that Wahlberg is not a cop anymore. When Wahlberg learns about the information, he does bring Damon to justice, in the only way he thinks possible.
-- At what point does Damon decide to end his double life and become a cop, before or after he finds out Nicholson is a rat? Second viewing I started to believe that Damon wanted out much earlier than I thought previously. Damon still worked with Jack because he wanted to find the mole (DiCaprio) and eliminate him because the mole may have known Damon's identity. When he learns that Jack is an FBI informant, he has to accelerate his plan. He only cared about himself. Damon tells Jack at the end, all that f***king and no sons. Jack did not want a heir, did not want to be replaced. No one could do what he did. But Damon (the closest thing he had to a son) was the one to finally take him down. Actually, DiCaprio in a sense was a better son. He tried to convince Jack to get out of the game and at the end, you felt that he almost didn't want to see him go down.
-- Is the rat imagery effective. I thought it generally was but I found it unnecessary and a little distracting at the end. The term of course refers to someone who betrays a colleague, friend, one's party, or beliefs/ideas. I think one of the main themes of the movie is why people betray and how or why they become corrupt. Power and self-preservation seem to have a lot to do with it.
-- Why is the movie called The Departed. I'm not sure. The phrase is used once in the movie to refer to a character early on who is killed. And that is what it means -- reference to a deceased person. But why title it that. The only thing that comes to mind is there is a lot of death in the movie (of characters seen or just referred to) and these events shape and inform some of the character's behavior and actions. Maybe he called the movie The Departed because of the powerful effect they can have on the living. Not sure though.