In its own times the book met with mixed reviews because of its unremitting darkness and weirdness, but in the 20th c. it became a hard and fast classic. In the Guardian it was even polled as the U.K.'s favorite love story - although I should say that the main theme is revenge and that it rather is a family novel (showing the decline of the Earnshaws and Lintons, and their fusion under the angry hand of Heathcliff) than a novel about love. Heathcliff and Catherine are at first more like brother and sister and Heathcliff's later passion seems to spring more from pride and self-love than a sweeter feeling.
It is not so strange that this novel with its violent acts and violent speech had to wait until the 20th c. to be loved. Heathcliff, too, is the kind of cruel beast without humaneness and compassion whom we know all too well from 20th c. history and fiction.
How come a pastor's daughter in a corner of England thought this all up in the mid 19th century?
Wuthering Heights is about large passions, but the style is rather bland and neutral. In contrast to Jane Eyre, the story is mainly told by bystanders and outsiders, like the long-time servant Nelly Dean and the tenant Mr Lockwood. The first three chapters do excellent work in setting the atmosphere and then we readers, too, are waiting for the story of Nelly Dean. But as it is difficult to feel sympathy for any of the characters in this family tragedy, you watch it like a storm on the heath, fascinated but strangely uninvolved.
I read Wuthering Heights in the Penguin edition. It is also available on Gutenberg. Librivox recording of the novel.
Interesting website about Wuthering Heights.