Good recommendations from SU2MM !
I would add Five Star Stories, though its one anime adaptation is just an hour long and I’m not sure where English translation of the manga is at. A lot of 70’s / 80’s Japanese sci-fi is similar in tone: Gundam at times, particularly the original TV series, or stuff from Leiji Matsumoto like Space Pirate Captain Harlock. The Lensman series was influential on LoGH and other contemporaries (for that matter, Foundation and Dune too).
On a smaller scale of intrigue there’s Stand Alone Complex, or if you’ve seen that, Joker Game. It’s political only in a subplot but I’ll still make this Syzygy recommendation in reverse for Lodoss. It is vulgar, violent and definitely declines in quality past a certain (arguable) point, but the early seasons of HBO’s Game of Thrones are really good. For that matter, play Tactics Ogre, or if you can’t make a commitment of hundreds of hours (shame!) this Let’s Play has commentary that goes deep into the political / historical side of it, and took years to get through it, changing hands several times.
Yeah!! Teito is great. As you say, its influence can hardly be understated: if you care for SMT, J-horror films, anything near that space it’s one of those seminal works that you are already steeped in references to it without knowing. The (kind of inauthentic) OVA adaptation billed as “Doomed Megapolis” is one of the first that jumps to mind when I think about the period when anime was called “Japanimation” in English. As for reading the serials, it’s of its time but if you are able I certainly think it’s worth it.
I think I love everything Amano has done cover illustration for. (The latter is Severian, @yeso )