Alternative Character Interpretation: Did Gilda really commit the first few murders or did Harvey's transformation into Two-Face cause her to snap and imagine she did? Likewise, did Alberto really commit all of the Holiday murders or did he just steal the identity after the first few murders and took credit for all of the murders? For that matter, it's hinted that Harvey might have committed some of the murders before he became Two-Face. There's also the question about whether of not Calendar Man really did know anything of the murders or if he was just using it as a grab for attention so he isn't forgotten.
Or, Alberto is a serial confessor (someone with a compulsion to confess to crimes), and that he only attempted the final murder, when he's captured by Gordon and Batman, and that all of the murders are commited by Harvey and Gilda, as suggested by the Calender Man.
Another suggestion is all three suspects committed some of the murders each.
Did Falcone actually know about Alberto's involvement in the murders? Batman certainly seems to think so, and there's a few clues to suggest it, such as him making sure Sofia isn't around to witness Alberto's attack on the Riddler. However, Alberto's chilly attitude towards his father at the series' end, as well as some of the more hard-hitting killings, cast doubt on this.
To what degree you read into the Sal/Sofia relationship will inform her actions at the end of Dark Victory; specifically, the murder of Alberto.
Alberto, a slight man with a .22 caliber pistol... versus Batman. In a kevlar vest. Reality Ensues.
Done deliberately with Carmine Falcone. After having been an invincible crime lord for ages, he's casually shot dead by Two-Face. It perfectly highlights how the old school criminals and mobs are powerless against the truly insane and nigh-unstoppable supervillains that are taking over Gotham's underworld.
Joker: Quick question. When the clock strikes midnight... do I get a little kiss? [Batman strangles him] Joker: I guess that's a no... [Batman punches him]
Also, Catwoman and Ivy:
Catwoman: You are mine, Poison Ivy. All mine.
Jerkass Woobie: Make no mistake, the crime families of Gotham are all made up of horrible people, but after seeing the horrible murders of their dearest friends and family, you will feel at least a little bit sorry for them.
A rare interpretation of Harvey Dent as this, too. He's no Apollo here, being much less friendly and morally unambiguous than usual portrayals, but he ends up paying a steeper price than almost anyone else over the course of the story. To boot, the "Father's Day" issue heavily hints that his established backstory is still in place.
Narm: Several lines/descriptions are repeated word for word several times such as "Carmine 'the Roman' Falcone, Gotham's untouchable Crime Lord" every single issue. It can get to "Dick Grayson, Age 12" levels of absurdity when read as a collection.
Drunken Riddler. The fact that he kind of looks like a Chuck Jones character in that moment doesn't help.
Can the characters get through a single issue without melodramatically saying another person's name in a hushed tone?
Alberto Falcone, full stop. That creepy but ostensibly upstanding young man? Yeah, turns out he's an utterly remorseless Serial Killer cherry-picking any potential threats to his father, out of a twisted combination of a genuine desire to help and egomaniacal spite. He manages to enlist the coroner to help him fake his death, allowing him to operate entirely outside the realm of suspicion. Regardless of whether you're in your house, a mob holdout or in jail, he's cunning enough to kill you and swaths of your associates with little more than a dinky little .22 caliber pistol or two and the element of surprise. And even if you're family, or even just a potential loose end, if he deems you a threat to him he still has no qualms about killing you. The worst part? It's entirely possible someone else committed some, or even all, of the murders. There could be one or two people out there, every bit as murderous, escaping justice.
Where as Two-Face's "scarred" side usually just looks discolored and deformed, Tim Sale decided Two-Face should actually look like half his face was burned off with acid complete with missing ear and lips. It's not pretty.
Rescued from the Scrappy Heap: Calender Man actually comes off as kind of serious, which is impressive given he spends the entire story in a padded cell.
Tear Jerker: Harvey and Gilda Dent start off as Sickeningly Sweethearts. As the book progresses, Dent's obsession with bringing in Falcone strains their marriage more and more. By the end of the book, their marriage is pretty much destroyed and both are dangerously insane.
Writing for the Trade: A rare inversion. The recap bubbles filling the reader in on who everyone is are vital for refreshing and understanding the story if you read it month-to-month, but reading in one go from the trade renders them rather repetetive (sometimes to the point of Narm.