I may have said this earlier on in the thread, but I'm about of this opinion myself. People love to talk about how great Watchmen is and how it elevated the comics medium (and it definitely is an all-time classic) but the gulf in quality and inspiration between it and From Hell is genuinely ludicrous. From Hell is the best thing Moore's ever written by a wide, wide margin.
I've always had this theory that Watchmen and
Twilight of the Superheroes were meant to be Moore's final statements on the superhero genre. Watchmen looking to the past and present of the superhero's place in modern American culture, and TotS looking to the future. Watchmen, of course, came off and was well-received (for many wrong-headed reasons, among others). But once DC didn't let him do TotS, he lost the inspiration to write superhero comics, and decided to look elsewhere to a different headspace and genre where he could really stretch himself (compared to From Hell, a lot of his superhero work seems
incredibly restrained conceptually). From Hell probably came partially from the frustration of dealing with DC, as well as the opportunity he was presented to explore the limits of what he conceived the comics medium could be independent of the DC machine. And from that we get something as excellent as From Hell.