VideoDrome. That one was much more representative of what I think of David Cronenberg's body of work, but this one was much more interesting to me. You probably couldn't classify it as a straightforward horror movie, but it's a good example of a psychological horror movie.
Jeremy Irons, who I really like (and who I have watched for my blog before), stars in a dual role as identical twins Elliot and Beverly Mantle. They are gynecologists with a highly successful practice, a history of research breakthroughs, and many professional recognitions. Elliot is the more outgoing and social of the two, with Bev being more of the lab rat/bookworm. They live together. They share everything. Elliot, who is also the more amoral, seduces women, and then passes them along to his brother when he tires of them, with the women never knowing. This pattern continues until Bev meets Claire, one of their patients, and falls deeply in love with her. When she finds out how the twins have treated her, though, she walks out on them, beginning Bev's slow descent into madness. His resulting actions risk his reputation, practice, and life, until he hits bottom, and the twins realize that much like Siamese twins, they must be "separated"...
Like I said above, this isn't strictly a horror movie, but it definitely has several of those trademark Cronenberg touches, including a bizarre dream sequence. Jeremy Irons gives a fantastic performance. At the beginning of the movie, you can clearly tell each twin's identity from his appearance and mannerisms. As they begin to slip, though, and lose their identity, it becomes harder to tell them apart, until the last scene, when it becomes impossible.
I give this one four speculums out of five.