Mid to late 80s DC is totally my jam. I’d say my personal fave DC run is hands down Keith Giffen’s Justice League, with Paul Levitz’s 80’s Legion run being a close second.
As far as Marvel stuff goes, my favorite run might actually be Garth Ennis’ Punisher MAX series. It’s definitely not as fun to revisit as say, Untold Tales of Spider Man, but it just goes for the jugular in a way that I can never shake.
Good point about Gaiman and DC continuity — the manner in which he effortlessly weaves in stuff like Cain and Abel and Hector Hall and Lyta Trevor in a way that doesn’t feel burdensome in the way DC stuff sometimes feels is a great illustration of why Sandman is a masterpiece of the medium.