About the only game prior to Arkham Asylum to capture the essence of the series would have been Batman: The Animated Series game on the SNES, but even that only aped the visual style, and missed the boat on the crime-solving detective aspects. Arkham Asylum was the first game that really let you feel like you were stepping into Batman's shoes. From using the shadows and verticality as your allies to take enemies down stealthily, to using the environment, gadgets, and good old-fashioned brainpower, Arkham Asylum and Arkham City delivered both content and the Batman "feel" with verve and panache.
Full disclosure; I never finished Arkham Origins because I felt like it took an interesting concept and threw it down the drain to cram the Joker in yet again as the prime villain. I'm pleased to report that with Rocksteady's final Batman game, Arkham Knight, the style and quality of the story have returned in spades.
Many moons (and many dollars) during pre-production marketing were spent on building the mystery of the Arkham Knight, one of the game's major antagonists. If you are versed with Batman lore, you'll probably figure it out a quarter of the way through the game, if it hasn't beenspoiled for you already. Even if you can see the twist from a mile away, some of the returning voice actors from The Animated Series, coupled with an above-average script handle the material beautifully and it's a joy to be a part of the story.
The game strikes a masterful balance between gameplay and story, capably delivering relevant material to you in sidequests, radio chatter, and Batman's dialogues with the various characters. Even if they do throw a lot of story material at you overall, it never feels truly overwhelming, and due to the game's impressive length, it doesn't feel cramped.
From a gameplay perspective, there's certainly a lot to do, and while most of it falls into a number of broad categories, the sidequest stories themselves and the situations keep the game's many missions feeling fresh. You'll solve tons of the Riddler's puzzles, rescue firemen, discover an arsonist's plot, train Azrael, clear the skies and the roads of the Arkham Knight's automated army, all of which are only a portion of the things you'll do during your time with the game.
I will say that they are very proud of their Batmobile content, as it is utilized in almost every plotline in the game in some fashion or another. Some like it, some hate it; I found that it controls well enough that it never really felt like a chore to use, although soaring through the skies on Batman's space-age glidey wings never gets old and just feels RIGHT.
Another thing that feels right is the combat. Arkham Origins' combat felt stilted, while Arkham Knight's is smooth, and makes you feel powerful. As you progress through the game's skill and tech trees, unlocking various cool takedowns and methods of mayhem to unleash on unsuspecting (and suspecting) thugs, the game rolls out new enemy types and configurations to test your prowess. There's never a dull moment.
Another thing that I feel deserves a mention is the quality of Gotham itself; it feels much more alive than in either City or Origins. While the city is locked down due to martial law and the invasion of the Arkham Knight's forces, there are riots occurring all over, and the rainy, grimy, neon feel of Gotham is in full effect. From the aging facades of Chinatown to the hyper-modern glass monoliths on the upscale Founder's Island, this vision of Gotham is breathtaking no matter where you look.
I would be remiss if I didn't note that the version of the game I played, the PC version, was released in, and remains in a pretty much unacceptable state. It's unstable, crashes all the time, performs horribly, and was even missing graphical effects seen on the PS4 and XBox One versions. Warner Brothers even went so far as to remove the PC version for sale from all outlets until it's fixed. Two months later and we've only seen a small patch that doesn't address the lion's share of the issues. The Xbox One and PS4 versions perform very well, and even recently received a large patch which added additional free features such as a photography mode. Even if you're a staunch PC dude or dudine (yes, that's the female version of dude), I would recommend getting the console version if you can't wait for the alleged full-on fix and re-release due in September.
As it stands, despite technical flaws in the version I played, Arkham Knight stands in my eyes as the best game in the series, and is well deserving of your hard-earned cash.