I'm sure folks would love a projected episode of Seaquest DSV.

(Started my post before the one above, maybe I was wrong. I liked the show, just not a big fan of projecting DVDs, especially if we are at the Grandview.)
Seriously, for the horror marathon, if we couldn't get Jaws, this might be a good catch, The Curse of the living Corpse.
http://imdb.com/title/tt0057985/ The doorway, would likely be a good fit, esepcially with IMDB tags like succubus, evil doll and female nudity.
http://imdb.com/title/tt0235353/ He also has a couple DTV Wes Craven Dracula movies.
As for Sci Fi, I wouldn't mind Blue Thunder. I just saw 2010 the other day and I like the idea of showing it in 2010. I was looking at his entries in IMDB (as evidenced above.) The Scifi pickings are a bit slimmer. Possible films he was in that might work at the scifi would be:
The Naked Lunch
The Punisher (as I recall he isn't in it much.)