Miller is one of the few comic artists with more than just a few movie adaptations of his works and in a lot of cases he had lots of luck with them. Take for instance the DC animated movies, which can be hit or miss animations-wise, and both Year One as well is this extravaganza two-part adaptation of Batman: TDKR look splendid and are pretty good when it comes to translating his stuff to the screen. I would go even so far in saying that if you’ve seen this adaptation, you don’t really need to read the source material (no wonder, Miller’s stuff always had a very cinematic style).
It’s an old Bruce Wayne going back to being Batman, saving his city from new criminals and a general lack of morals, showing all who is the king, even Superman who is later sent in to stop him (because politicians don’t really like vigilante justice, especially when they are good at it). When I read it as a kid I loved TDKR unquestionably, now I still like it (though it really lacks the same punch as seeing or reading it for the first time). Miller has gone of the deep end in recent years and some signs for that development can be seen in nearly all of his earlier work, but TDKR and others still work quite well despite all that.
There’s eyebrow raising stuff here (most of all the cold war era things feel out of place), but overall pacing, the action and the plot are all fine. On the surface, TDKR became famous because it depicted a grim’n grittier variant of Batman than at that time most of his contemporaries did. But the undiminished allure of it is because it present a version of Batman’s future and final days that feels legitimate. Not an Elseworld story, but the real thing, the perfect ending to Batman’s story, if that would ever be allowed to happen. That hasn’t changed in all these years.