These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: The Dark Knight Returns and The Dark Knight Strikes Again presented Batman as a dangerously-obsessed, deeply-disturbed, paranoid, control freak who is possibly a mentally ill Sociopathic Hero as opposed to the stalwart Caped Crusader of the Golden and Silver ages and the Adam West series. This interpretation is touched on Depending on the Writer and sometimes it is the basis for whole story arcs.
One example is his creation of the Brother Mk I satellite which was created by Batman to keep an eye on all of the meta-humans, hero and villain alike.
Another story, Tower of Babel, centers on Ra's Al Ghul obtaining a file containing Batman's contingency plans to cripple each and every member of the Justice League "just in case" and using them to his own ends. The existence of the files and the secrecy under which they are kept infuriates The League and leads to his expulsion.
Complete Monster: The Joker and The Mutants to name a few, but Byron Brassballs shows that you don't have to be a twisted criminal or a rowdy teenager to be an incredible jackass by beating a helpless priest and pushing a handicapped man in front of a subway train, and then remorselessly trying to justify his actions when being interviewed by the news (both times).
The depiction, manner and philosophy of the Mutants are frankly eerily similar to the more abusive "Anonymous" cells online. Bear in mind, this is referring to the steal-your-identity-and-send-you-death-threats type of Anonymous and not the image board type of Anonymous.
Two-Face trying to destroy Gotham's Twin Towers with a bomb, seven years before the same thing was attempted on the real Twin Towers with a car bomb. Later on, of course,a 747 crashes into same said towers, destroying them and setting Gotham on fire. Fourteen years before the same thing happened in Real Life.
Hilarious in Hindsight : This came decades before the meme actually started, but take a look at this quote:
Mutant Gang Member: (after being attacked by a bat) It's just a goddamnedbat.
Take That: The Mutants can be seen as a Take That to "angsty", rebellious teen superheroes made popular by Marvel Comics. They're named the Mutants (Stan Lee's working title for X-Men), they wear red shades that look a lot like Cyclops' visor, and they despise adult authority figures. They form a perfect contrast to Batman, who's the epitome of the "traditional" DC superhero—an adult superhero who's driven and fearless, and has zero tolerance for crime.
And the Fandom Rejoiced: The fact it's getting made, for starters. The casting of Peter Weller as the voice of Batman was also met with general fan approval.