For me a full restoration of William Blatty's Legion.
I can at least replenish my memory of the OOT with the preservation project work of people on these boards.
Blatty's film (royally screwed over and released as The Exorcist III) has only been seen by a hand full of people.
Watching this film as it was intended to be seen is one of the few things I want to see before I go elsewhere.