Coma (1978) is without a doubt one of the best films I've ever seen. Imagine you go to the hospital, routine surgery, go under....and DON'T WAKE UP? That's a terrifying prospect. This film isn't a horror film, it's a suspenseful crime thriller that starts off feeling like a drama, sort of like lulling prey, the viewer, into a false sense of security, but as the heroine digs deeper, and deeper into the truth, putting the pieces together and getting closer to terrible conspiracy of why patients going under for routine surgery are coming out brain dead, and soon afterwards fully dead, the danger, the fear, the terror and suspense builds until the climax where you're gritting your teeth, knowing what's about to happen and hoping that it can be stopped in time. I definitely recommend.