Yup, I read the classic Batman paperbacks in the most hipster order possible. I don't regret it. So I guess the real question is: were the Amazon reviewers correct? Is The Man Who Laughs a better encapsulation of the Joker/Batman dynamic? Well, no, I don't think so. The Killing Joke (despite having been thoroughly spoiled online for me multiple times over) definitely lived up to the hype. It is a brutal, ceaseless, gut-wrenching analysis of both characters and the definitive outline of the Joker, both as a person and as a villain, in a way that The Man Who Laughs is not. I can understand the comparisons and, perhaps, as an origin story The Man Who Laughs is more complete and more compelling as a result, but personally that feels slightly wrong. The Joker should be an enigma, with the artist behind The Killing Joke even stating that the "origin" portrayed in its' pages perhaps should be interpreted simply as one of the possible stories the Joker's fractured mind has coalesced around, without any weighting of truth or fact about it. Personally I feel that may be a step too far, but the ambiguity to the mythology is far more nuanced than the heavily-hinted but ultimately not confirmed origin portrayed in The Man Who Laughs.
Comparisons aside, as both are fantastic stories worthy of anyone's attention, The Killing Joke is genuinely stunning. I was expecting that to be the case (frankly you'd be ignorant not to, given the level of critical and fan acclaim) but I was still surprised by how much the craftsmanship exceeded my expectations. The script, in particular, was brilliant; Alan Moore is regarded as a master of dialogue but I think this is his finest work (that I've had the pleasure to read, in any case). Not a single word was out of place and both the opening line and final interplay were exacted with pinpoint precision that left me stunned and forced me to reread them both several times over. The phrases, puns and linguistic choices throughout were (almost) flawless. My one niggle would be the initial interaction between Batman and the fake Joker, which felt a little out of character, although I will admit that the Batman I know and love must certainly have evolved since the novel was written. Indeed, though this is a Batman story in name, Batman himself is very much a bit player. Truly, this is a story about the Joker, told by the Joker and for the Joker. That it also manages to give an insightful and poignant outline of the core relationship between the two characters only goes to further show its genius.
Personally, the artwork felt a little dated (as I would expect, given the publication date) but its tonal quality cannot be undermined. The Joker's malevolent gang of carnival stereotypes are truly unsettling in their portrayal and the entire funhouse sequence is breathtakingly executed. As I read the modern re-published edition, I can only comment on the digital colouring that was redone for that run, but I would say that the book looked fantastic. The use of colour in the flashback sequences is particularly notable, but the whole story was beautifully done. Perhaps a little garish here and there, particularly for Barbara's initial scenes, but again a nitpick rather than a true criticism.
Finally, on the note of Barbara Gordon, I feel it wrong not to at least mention that scene. I've heard plenty of arguments about it, but ultimately felt it was played very well. The whole story was dark, right from the start, but the shooting of a major character in such cold blood (and so early on) made that tone concrete and gave the entire plot an anchor point. Insinuations that rape was too dark, I feel, are a little overplayed. Each person will read that scene differently and I haven't researched whether the creators themselves have gone on record as to what happened "off-page", but to me it didn't read as rape. Declothing her, showing her completely vulnerable and dying, just helped emphasise the Joker's psychological tactics; jumping to the conclusion of rape occurring is out of character for the villain and also didn't feel inherent to the script. But that's just my two cents.
As for the other scene iconic for its ambiguity, the ending shot, I have to say it didn't quite hit the target for me. The joke was on point, but what happens next, personally, just felt like a writer leaving it open-ended because there was no way to end it. Did it work? Yes. I have no qualms with leaving the story without a definitive conclusion, indeed I think it fits nicely, but do I think Batman, there and then, strangled the Joker? No. In fact, for my own personal headcanon, I see everything after the close-up of Batman's face and "heh" dialogue as taking place in Batman's head; the action he wants to take, feels he should take, but can't, hence his own maniacal laughing. Perhaps it's even the Joker's own desire, the ending he wants, given so much of the story seems to be from his point of view rather than the readers or Batman's. Ultimately, though, who knows? And isn't that the whole point?