I revisited E. T. A. Hoffmann's The Sandman, which Freud discussed in his paper on the uncanny. Written in the early 1800's, Hoffmann's tale anticipates more recent fiction involving automata. E.g., in The Sandman, a character falls in love with Olympia, whom he then discovers to be a robot. Freud notes that this strand of the narrative isn't the source of the story's uncanniness, and that, if anything, Hoffmann puts the automaton to a humorous, satirical use. E.g., once Olympia is exposed, Dr. Spalanzani, one of her designers, has to flee to "escape a criminal charge of having fraudulently imposed an automaton upon human society," a crime that sows "an absurd mistrust of human figures." Indeed, to be sure they're not dating robots, men start requiring their girlfriends to demonstrate their human imperfection by singing and dancing out of time, which is a very different male response from the one in Ira Levin's The Stepford Wives (where the realization that one is dealing with an automaton is uncanny). A similar motif animates one of the best episodes in the 1960's TV series The Outer Limits. This 1964 episode, 'Demon With a Glass Hand' (written by Harlan Ellison & starring Robert Culp), presents a woman's response to the discovery that she's fallen for an automaton -- she screams and runs away.
Update (Sept. 26, 2009): According to this Wiki article on the 'Uncanny Valley', real automata inspire only revulsion.
Update (Sept. 27, 2009): Unsurprisingly, there's also an old Twilight Zone episode featuring a relationship between a human person and a automaton. It's called 'The Lonely'.
Update (Oct. 4, 2009): And of course there's a Star Trek episode (from the original series) to be cited. It's called 'What are little girls made of?' It featured several 'androids', the best one of which was the obvious robot, Ruk (who was played by the same guy who played Lurch in the Addams Family).