I agree that The Return of the Living Dead would be badass. Others that I'm sure have already been mentioned, but whatever...
The Thing (Negative blood test video clips for locking balls. Positive for starting multiball). A lot could be done with this one IMO.
Night of the Creeps (the most underrated 80's horror flick, and admittedly a pipe dream of a theme that will never happen)
They Live (imagine UV lighting or something similar that makes the playfield physically look different in certain modes)
The Monster Squad
The Burbs (sooooo many great quotes)
Creepshow
The Shining
Young Frankenstein