Here's what I'm familiar with in zeuhl & RIO (and throw in some jazzrock and prog rock):
Magma – one of my favourite bands. Got everything that counts by them and there's nothing I don't like to at least a certain extent (save for some live albums)
Univeria Zekt – only one album (The Unnamables). Recorded, I think, at the same time as the second Magma album, it was pretty accessible jazzrock (which at the time was Magma's style too, although in a strange way) in an attempt to get more Magma fans. It's not a bad listen by any means, but overall a little too commercial (I especially don't like the singing)
Christian Vander – the boss of Magma, his solo albums are also great. They're different from Magma and very hard to describe. He also has jazz albums which are also good, some of them great (the best I think is his Alien trio CD)
Offering – another Vander and Magma-related band with great releases (although there are weaker moments here and there)
Fusion – Vander was involved again; they only have one album (from 1981) and it's great. Not jazz/rock fusion as the title might imply, it's more... electronic/rock jamming (with the occasional violin)
Weidorje – only one album (s/t). Classic zeuhl, but I think only about half the songs are good
Paga/Bernard Paganotti – used to play in Magma; has a few solo albums of which I only know Paga which has some very good zeuhl parts
Shub-Niggurath – one album as far as I know. I find it boring and annoying after a while. Read a lot of rave reviews about it before hearing it and was I disappointed when I finally heard it!
Zao – I believe the founder used to play in Magma. I only know their album Shekina which is jazzrock and has some really good themes. I'd say about half the album is great, the rest isn't bad either, just not very exciting
Univers Zero – love them! Of their second phase (from the 90s onwards) I only know one album (Implosion, I think) but would love to hear the rest.The 70s and 80s stuff is very dark chamber rock. Implosion is somewhat lighter and I've read so are their other newer albums
Daniel Denis – main man in Univers Zero, has 2 solo albums I believe. I know one, it's very good, similar to UZ's Implosion album in that it's lighter than "classic" UZ (it's still not pop music though, of course)
Present – main man used to be in Univers Zero. I have their first 2 albums (available on 1 CD) which are great. Similar to UZ but with more electric guitar
Art Zoyd – only know Symphonie pour le jour où brûleront les cités which was their first album but then a few years later they re-recorded and re-released it under the same title. I have the second version (reissued by Sub Rosa last year). It's somewhat similar to UZ but more classical in approach. I must admit I still don't know how much I like this album, despite having heard it maybe 10 times. It's very demanding and cold, so I gotta give it a few more spins still
Patrick Gauthier – his first album (from 1980), Bebe Godzilla, is one of my favourite albums ever. Discovered it early this year and I already must've heard it 50 times. It's a wonderful mix of zeuhl, prog rock, psychedelic music, beautiful melodies and quirky themes. Gauthier used to play in Magma, Weidorje and Heldon. He made 2 more albums in '93 and '96 respectively, but while they have good moments, they're surprisingly commercial (and crap)
Jean-Philippe Goude – another ex-member of Weidorje. His 1979 album Drones is a great mix of zeuhl and unusual prog rock. Too bad I don't know his other albums
Jannick Top – ex-bassist of Magma. I only know his Soleil D'Ork album which was a disappointment. I remember liking about one song (which was great zeuhl), the rest was uninspired
Benoit Widemann – has 3 albums, Tsunami, Stress and 3. They're solid synth/rock albums with a touch of zeuhl. Some of the songs stand out for having lovely melodies and if they were all like that, his albums couldn't be beat
Heldon – I only know Interface which I guess is their most famous album. I absolutely love the parts with synths or synths & drums, but when the electric guitar comes in, it goes downhill for me. I can't stand guitar wanking and sadly there's a lot of that on this album. Roughly half of it is still awesome
Richard Pinhas – only know some of his solo albums: Rhizosphere and Chronolyse (great psychedelic synth albums, especially Chronolyse), Metal/Crystal (pretty good) and Keio Line with Merzbow (I also remember liking that one)
Ruins – I like them, although not their early stuff which is too spastic for my taste. Burning Stone has some of the best songs I've ever heard (although not the entire album is great) and sadly they didn't continue with that style. However, I like their later albums too (even if I could do without the high-pitched vocals). The Sax Ruins album is especially good (Ruins songs played on saxophone and drums)
Korekyojinn – probably my favourite Tatsuya Yoshida project. They play mathrock, perhaps? (I don't know what that term really refers to). Unusual riffs and rhythms, sometimes very catchy melodies. My favourite album might be Isotope
Koenjihyakkei – I like their first album the most (Hundred Sights of Koenji). It's a bit like a spastic Magma. Later albums are often quite tedious, but all of them have some good parts
Bondage Fruit – I'm pretty sure I've heard all their albums (6 in total perhaps) but I could never get into them. Maybe I'll give them another try
Zamla Mammaz Manna – Schlagerns Mystik is a great album. Quirky, weird, humorous (rock?) music. För Äldre Nybegynnare, on the other hand, is a terrible improvised album that goes nowhere. Don't know their other albums, sadly
Henry Cow – I've listened to a few of their albums but I couldn't really get into them. I don't know why. I'll have to give them another try