Daicon III and IV Opening Animations
Laserdisc and other Media
Despite the fact that they were available on laserdisc (LD) starting in 1988, the Daicon Opening Animations were never officially released in Japan. The reasons are a bit complicated and somewhat unclear. Here's my understanding of the situation:
Gainax themselves (or Daicon Film, rather) didn't have the rights to use the various bits of music (that they took from here and there) featured in the Daicon Opening Animations. Most notable is the ELO (Electric Light Orchestra) track "Twilight" used in the Daicon IV anime. (The ELO tracks "Prologue" and "Hold On Tight" are also used on this disc.) They also didn't have permission to use the Playboy bunny costume. To get past this legal inconvenience, perhaps, the Daicon LD is labeled "not for sale" (in Japanese). One had to buy a "making-of" book in order to get the LD as a "freebie". Never mind that you had to pay 16,000 Yen for the book...
The fact that Gainax didn't have the rights definitely contributed to the Daicon anime not being sold in the US. Back in 1989, when Gainax had an American division called General Products USA, they wanted to sell the Daicon anime. They needed to acquire permission for both the ELO music and the Playboy bunny. The Playboy people (who Gainax contacted first) didn't like the idea, so that project was scrapped. (ELO was not contacted).
Gainax has released several other Daicon Film projects (all of them live action) on R2 DVD, but there still isn't any sign that they're planning to release the Daicon animations on DVD. It's possible that the legal issues still make that very difficult, even in Japan.
Only a very limited number of Daicon LDs were pressed. The Daicon animations were released on video as well, but the videos lacked the permanence and quality of the laserdisc version. Because of their rarity and Gainax's cult status, the Daicon LDs are highly sought after, fetching incredibly high prices at auction (anywhere between US $1,000-1,500) in both Japan and the United States.
[In case you were wondering...Yes, I do own a Daicon LD (pictured below), but it's not for sale.]
The video tape release of the Daicon III and IV Opening Animations features different bonus material. On the tape version, The Revenge of Yamata Orochi is replaced by Kaiketsu Notenki.
Putting on the Daicon III event left the organizers in debt, so they sold video copies of the Daicon III Opening Animation to recoup costs. Unverified internet sources seem to indicate that those videos were released on Compact Video Cassette (CVC).