I remember doing it for the Hifuu albums a few months ago, but not for the games.
I think all of the albums have some good stuff. Almost every album has a handful of memorable songs but a few just don't click right. Top of my list are IN and PCB, nearly every song is a bangin' tune. Bottom of my list is for some of the same reasons as you, though while I do like some of the remixes in UDoALG they're remixes, but The World Is Made in an Adorable Way is a fun jingle that keeps coming back into my head. Much of the ground fighters music is okay, but doesn't knock it out of the park and are structured to fit the format of a background battle track or short loops which I don't care for as much. I think the flying fighters do a lot better and really have some standout tracks.
The PC98 songs are not ones I've listened to their originals much, my memory of individual songs from them comes from the Akyuu's Untouched Score volumes and Hifuu Club.

>>146850
Yeah I prefer the Akyuu's Untouched Score versions as well, they're basically the only way I listen to the PC98 soundtracks anymore. I'd recommend giving the 17.5 OST a few listens, lots of great arranges and Yuuma's themes are some of ZUN's best recent work. Also took a crack at ranking the albums cause why not. Magical Astronomy on top is probably a pretty common take lol.

I really can't remember them as a group so would have no idea. Do the songs really sound similar enough to each other in each soundtrack, apart from the typical stage and boss similarity?

>>146871
Yeah, I consider individual songs more than albums. Usually if I do compare two songs it's only as stage to boss music.

>>146871
It's not so much that they sound similar to each other, although some of the games have a pretty distinct sound to them, usually because of the instruments used. I'm moreso evaluating each soundtrack on what I perceive to be it's overall quality. Basically, how much of the soundtrack do I think fucks vs. how much of it I'm indifferent to, and how hard those tracks fuck. So, to rank highly, an album would need both consistency as well as standout tracks, which I think PCB and IN have. Something like MoF, for example, is imo just as consistently good as those two in that I like practically every track on it, but doesn't quite hit the same peaks in terms of specific tracks, so it ranks slightly lower. Obviously this is mostly personal opinion.

EoSD is one of the greatest achievements in modern music.
PCB and IN are consistently great.
UFO is not as consistent, but has a few of the best tracks in the series, and a really unique sound.
If I'm being honest, StB and DS are mostly not that remarkable except for one god-tier track (Retrospective Kyoto and Bell of Avici, respectively), they get bonus points because I love the games themselves.
Not much to say about the rest except that I stopped following the games after HSiFS, and I don't care much for the post-UFO games. But among them I do have a bit of a soft spot for DDC.

>>146879
>I stopped following the games after HSiFS, and I don't care much for the post-UFO games
I recommend you give later games a listen to at least. LoLK, AoCF, and WBaWC have some superb songs. Idolatrize world, tonight stars an easygoing egoist, star spangled pierrot, pure furies, unlocated hell, and faraway voyage of 380,000 kilometers are some. Yorimashi between dreams and reality from AoCF is a fun one since there's a version on the arrange CD (U2 Akiyama) that is cute if you consider the ZUN original to be how others see her vs the arrange being how she sees herself.