I saw Batman Begins last night and it's my favorite in the series thus far. I don't think I've ever read any of the comics, so I can't say how true the movie is to the sources, but it sure was fun to watch. Without being preachy, it was also one of the most solid and viscerally moralistic movies that I ever remember seeing. Spoilers follow, obviously.
I didn't completely buy into the motivations of the League of Shadows, though I liked Ra's Al Ghul's interactions with Batman. The differences between the moralities of the two characters was subtle and mostly came down to a question of implementation, but the movie dealt with the contrast cleanly, for the most part, and presented both sides of the issue. Ra's Al Ghul wanted to fight evil by destroying the city, writing it off as a lost cause, wheras Batman recognized the evil but didn't believe that the city was beyond redemption. Realistically, humanity has no choice but to hope for the latter.
There are all sorts of nits to be picked, but I'll lay off the science since it is a superhero movie. However, am I the only one who found it unrealistic for Katie Holmes to turn billionaire crime-fighter Bruce Wayne away just because he hadn't "found himself" yet or somesuch nonsense?
Finally, Christian Bale was a great Batman, and again, my favorite thus far. Liam Neeson did a great job. Katie Holmes' character was well written (except for the rejection of Wayne near the end) and understated, and she pulled it off well. I also enjoyed Gary Oldman as Jim Gordon, Michael Caine as Alfred, and Cillian Murphy (best know to me from 28 Days Later) as Scarecrow.