From a computer's mind... and a woman's body... a new generation of screen terror is born.
Based on a Dean Koontz novel, Demon Seed (1977) is an incredibly creepy sci-fi flick about a woman (Julie Christie) who becomes trapped inside a self-aware computer-controlled house. The computer in question - Proteus - is somewhat hilariously described in the trailer (included after the jump) as a "murderously intelligent, sensually self-programmed, non-being." There are moments of tedium, but it builds to such an unsettling end that I can highly recommend the film for anyone that hasn't seen it.
Click through for the MGM UK box art and the film's trailer.