After Crying are probably the most well-known Hungarian avant-prog band, often considered to be the best RIO-influenced band in their country. Personally I heard only two albums out of their considerably big discography, and here's my favourite one. I think the album cover says all about the music - the atmosphere it creates is as quiet and melancholic as winter forest at night. Don't know how to express it better...
One more album by Samla Mammas Manna, full of silly humour, circus references, excellent musicianship, and everything else that SMM are known for. Personally I like this one and "Klossa Knapitatet" more than "Måltid" (widely perceived as their best albums), or their later works under different names ("Zamla Mammas Manna", "Von Zamla", Lars Hollmer's solo albums), characterized by somewhat more serious approach to music.
Samla Mammas Manna were one of the 5 original RIO bands (along with Univers Zero, Henry Cow, Stormy Six, and Etron Fou Leloublan; later followed by Art Bears, Art Zoyd and Aksak Maboul), but their music is actually rather far from RIO. SMM undoubtedly were virtuous musicians, but they preferred to play much more lighthearted music strongly influenced by Canterbury scene and Swedish progg movement. Seems like they also shared the ideology behind the progg scene, as the album name,"Klossa Knapitatet", is an obvious pun on "Krossa Kapitalet" ("Smash the Capital").
Ugly album cover, but beautiful music. It's the only album by Miriodor I've heard so far, and it's quite good (I heard all their later albums are better, though). Not sure if they're comparable to 80's Art Zoyd, Univers Zero and other RIO bands (I think Miriodor are more melodic and not that overtly "avant-garde"). But just like in case with Art Zoyd, I can surely say it's music for listening at night.
Here's my favourite album by RIO classics Univers Zero. It's definitely nowhere near as "dark" or avant-garde as their classic releases like "Heresie" or "1313", but I like the mood and atmosphere of this album (as well as the cover art). Maybe I'm not a real fan of avant-prog, but I never pretended to be one :P Anyway, here's the kind of progressive rock I like the most - melancholic, "cosmic" (as opposed to UZ's early releases, which carry a "creepy", horror-movie atmosphere), melodic yet full of electronic noisy parts.
"Most of AHVAK members met through an internet prog-rock forum in Israel. They started rehearsing but didn't work seriously until drummer and composer Dave Kerman (5UU'S, THINKING PLAGUE, U-TOTEM, PRESENT etc.) came to Israel and joined the band. Their debut album was released on Cuneiform Records in the USA and got some pretty flattering reviews" (progarchives.com)
Besides that, not much is known about Ahvak. Don't even know if they recorded their 2nd album, but their debut one is quite interesting. It's probably the one and only RIO-influenced avant-prog release from Israel (correct me if there are any others).
Along with Univers Zero, Art Zoyd are probably one of the best known bands in the whole Rock In Opposition movement. Most of their albums aren't that hard to find, so I won't post their complete discography here. However, I'd like to post one of their lesser known, but nevertheless great albums - "Le Mariage Du Ciel Et L'Enfer". Recorded in 1984, this album isn't as "electronic" as their later releases, but no less "dark" and experimental. According to the release notes, "Le Mariage Du Ciel Et L'Enfer" is actually music for some ballet by Roland Petit. Unfortunately, my knowledge of ballet is very limited, so I won't comment on this...
Another French avant-prog band, strongly influenced by Rock In Opposition movement (but significantly heavier than most RIO bands). Here's their third and most recent album, "ZePTo" (capitalization rule - all consonants are in capitals, unlike the vowels). Besides the obvious references to Crowley ("Do What Thou Wilt") and Lovecraft ("The Old Ones"), the album has a strong futuristic feel, and creates a "cosmic" atmosphere. Happy Cosmonautics Day, BTW!
"SHUB-NIGGURATH was formed in 1983 and consisted of six musicians: Allan Ballaud on bass, percussionist Franck Coulaud, Frank Fromy on guitar and percussion, Jean-Luc Herve on harmonium, piano and organ, vocalist Ann Stewart, and a trombone/bass player Veronuque Verdier. The band released their first untitled demo on 1985 and got good feedback from critics. The promising debut album, "Les Morts Von Vite", was released on Musea label in 1987. The album received good reviews and is their finest moment: it caught the band at the peak of their creativity. Musea reissued this album on CD in 1997, including two rare bonus tracks. The debut sold well and later, in 87, SHUB NIGGURATH's song appeared on Musea's Zeuhl compilation "Enneade", a tribute to the legacy of Magma. [...] SHUB-NIGGURATH's best album is the debut, and it's also the best place to start exploring their music. However, their career has been fairly consistent and the other two albums are quality efforts. If you like dark, brooding mix of RIO and Zeuhl you will like SHUB-NIGGURATH. their avant-ish dark prog with a sharp edge is both unique and challenging"
While I can't say this album reminds me of Magma, it's definitely a classic and should be recommended to anyone who wants to hear some progressive rock that's really hard to get into. The atmosphere on "Les Morts Vont Vite" is quite dark, but what else to expect from a Lovecraftian band?..