You all will probably be shocked to hear that . . . I thought this was very good.
My reaction may have been helped by my having ramped my expectations down. I inferred from reviews (and confirmed from someone who'd seen it) that I could expect two plot elements, one of which is not to my taste and the other of which I really doubted could be done well. But the first was handled relatively non-sporkily, even if I still would have preferred something else, and the second worked much better than I expected. And I'll give a movie a lot of leeway for head-on engaging with hard questions that Iron Man, for instance, just shrugs aside.
(Speaking of which, I highly recommend The Kids Aren’t All Right: Politics & Power: vanityfair.com, which is fanfic set a year after the end of the movie and done as a pitch-perfect article by Christine Everhart, complete with glossy magazine page mockups. If the movie had been half that smart and complex, I wouldn't have been so bored with it.)
Back to The Dark Knight—so, plot better than I expected, and also, really quite an intense experience. Even at two and a half hours—at one apparent-lull I got up to go to the bathroom, looked at my watch, and said to myself, "I can't believe we still have another hour to go." But when I got back things had jumped into high gear and I don't think I looked at my watch again.
Anyway: Heath Ledger's Joker is indeed astonishing (and, good grief, people, not something to subject your five year old to! There were points at which I thought the movie was almost too dark for almost-thirty-one-year-olds!). The low-key supporting players (Michael Caine, Gary Oldman, and Morgan Freeman) were delights. Christian Bale was unobjectionable, which is all that I ask in a Batman, considering, as were Aaron Eckhart and Maggie Gyllenhaal. The action sequences were exciting and visually impressive without killing the entire movie under their weight, and while occasionally they did rely on action-movie lack-of-logic, I was willing to roll with it.
In short: good stuff. And since I suspect this is the end of our new-release summer movie viewing, yay, ending on a satisfying note.
Right, so, the two plot elements I expected were actually part of the same thing: Rachel gets killed horribly to trigger Harvey Dent's transformation into Harvey Two-Face. Which, first, whee, another woman in a refrigerator! And second, in a movie that already had the Joker, is there really room for another villain?
Well, I still am not quite satisfied with the Rachel thing—yes, true, she wasn't lingeringly raped and tortured to death (*rolls eyes at having to be glad about that*), but as a motivation for Harvey's transformation, I think I would have preferred it to be part of a larger destruction of faith that combined the personal and the professional—maybe make her the target of the Joker's threat to blow up a hospital and have a cop succeed, or something (she says, airily, through her fatigue). But, anyway, I'd resigned myself to her death as a plot element, and it could have been worse.
As for Dent to Two-Face: this worked a lot better than I expected, and I think part of it was the length of the movie. Looked at as a whole, I think one could make a very good argument that the movie is actually about Two-Face and not the Joker, for all that he's the one in the previews. At which point it's not just throwing in another villain at the last minute, it was all leading there from the beginning. And in a more gradual and therefore more plausible way than I was expecting, too, again with the caveat above.
The other spoiler thing of note to me is the scene on the ferries (which, yes, really should have been checked for traps before putting off . . . ) On one hand, of course movie logic demands dragging that out past midnight, for all that I'd hoped that someone would immediately and reflexively just toss the things out the window. On the other, it made the eventual payoff feel earned—especially since, in this movie, I really didn't know which way it would come out. And not hooray-uplifting but skin-of-teeth-escape from our own worst nature—note that on the prisoners' boat, it comes about through an acquiescence to force, and you can't tell me that the guard was supposed to have understood what the prisoner was going to do, even if in retrospect (as Chad noted) his resemblance to Michael Clarke Duncan, who played the Magical Negro of The Green Mile, was striking . . .
(Compare the scene in Spider-Man 2 where the people on the train pass Spidey from hand to hand overhead, like he's Jesus or the Sleeping King, which was just too much.)
Finally, not even Gary Oldman can pull off that awful end-of-movie monologue. (As Chad noted: how weird is it to see Gary Oldman playing subdued? Not what you usually cast him for. But I enjoyed his character a lot, with the minor caveat that I'm not sure whether his blindness about the bus hostages was plot-induced stupidity or intentional stupidity to prove that no-one's perfect and everyone likes things to go as planned. Also, I was completely faked out by his death, and expected the driver in the full-face helmet to be a Joker henchperson.)
(Oh, and it stands alone just fine. There's one little bit in the beginning that doesn't make sense if you haven't seen Batman Begins, the drug dealer in the odd mask, but it really doesn't matter.)
(Additional note: there is a series of special effects late in the movie that I found motion-sick-inducing, but if you're prone to that, you'll spot them almost immediately, and you won't miss anything by squinting through them.)