From December 1979 (although this hails from much later): Disney's Star Age would-be blockbuster THE BLACK HOLE.
Despite the numerous - and sometimes obvious shortcomings - I rate this as one of the icons of the era. Both because it's an entertaining - and spectacular - movie in its own right but also because of the ubiquitous merchandising it spawned.
This is the UK sell-through VHS cover. I think this is one movie thst really demands a bells-whistles-and-B.O.Bs BR release.