The Fly (1986)
IMHO it's the best Cronenberg's movie. The plot is well written, the actors well chosen, the FX amazing, and it has gore, lots of gore.
Seth Brundle: You have to leave now, and never come back here. Have you ever heard of insect politics? Neither have I. Insects... don't have politics. They're very... brutal. No compassion, no compromise. We can't trust the insect. I'd like to become the first... insect politician. Y'see, I'd like to, but... I'm afraid, uh...
Ronnie: I don't know what you're trying to say.
Seth Brundle: I'm saying... I'm saying I - I'm an insect who dreamt he was a man and loved it. But now the dream is over... and the insect is awake.
Ronnie: No. no, Seth...
Seth Brundle: I'm saying... I'll hurt you if you stay.