I loved
Macbeth and it was reading that play that got me into Shakespeare, but I wouldn't recommend reading the original if you don't speak English extremely well. I'ts one of the most difficult, if not the most difficult of Shakespeare's works in terms of language - not because of the outdated words (that is not a problem if you have a good edition with notes and a dictionary) but because of Macbeth's soliloquies which are full of complicated phrases.
I find it very odd that some posters found
Wuthering Heights boring or couldn't like it until later in life, it shows you how we're all different. I first read it when I was 12 and adored it to the point of obsession (granted, I probably wasn't a typical 12-year old...), and re-read it multiple times over the course of the next year or so. That was in translation, though - I first read it in English at the university (3rd year) but it was easy to read, apart from a supporting character called Joseph who speaks in a thick Yorkshire accent (and it is made obvious in the writing, which makes his words near unintelligible, but it's not particularly important, you just need to get the general gist of what he's saying). I found WH as impressive at 22 as I did at 12, it's a timeless classic IMO (and pay no attention to any of the film adaptations, which are mostly sanitized and simplified Hollywood garbage).
Out of the other 19th century authors, I recommend Thomas Hardy, and some of the better Dickens novels like
Great Expectations.
I also find it funny that people just throw Emily Bronte, Charlotte Bronte and Jane Austen together as if they're the same, when they're not even remotely similar. I guess it's a case of "they all had a vagina, so they're the same, it's chick lit, right?"
Jane Eyre is more conventional in its narrative technique and attitudes than
Wuthering Heights, though it was in its time quite revolutionary itself, with its representation of a young independent woman, and of a female desire and passion (something that was deemed shocking in Victorian age when
good women were just supposed to be passive 'angels of home' who only sleep with their husbands out of marital duty and devotion to family) but from today's point of view it's just a tame little romance, a little naive and outdated. There's a great book of feminist criticism called "The Madwoman in the Attic" that derives its title from that novel, and it contains a great analysis of
Jane Eyre (as well as
Wuthering Heights and many other books of 19th century literature written by women) from the historical, psychological and cultural point of view.
Jane Austen is... well, very different. I am definitely not a fan, but
Pride and Prejudice is OK as far as she goes. While Charlotte Bronte's work was full of emotion if a little naive at times (I think she would more aptly be compared to Dickens; they both criticize some aspects of the society, and tug at the heartstrings in the process, and their books tend to feature a young protagonist who is poor, orphaned, etc. dealing with life's hardships), Austen is very level-headed and rational in her portrayal of the English middle class society, and whatever anyone will have you believe, the matchmaking described in her novels has at least as much to do with social standing and class issues than with any romantic feelings.
As far as classics go, you could also try Thomas Fielding - his
Tom Jones is a long novel, but it is fun, easy to read (you'll see that 18th century language wasn't really that different or difficult to understand, as long as the author wrote in simple, everyday language), and more colorful and lifelike than Victorian literature in many ways... let's just say that English culture of 18th century wasn't nearly as repressed (especially sexually) than that of the 19th century, so after you've been used to the ridiculously 'chaste' Victorian mainstream novels, Fielding is very refreshing. He has some very modern humanist ideas and criticized false morality of his day (such as can be found in some other 18th century authors that I was forced to read at the university).
As for American literature - I loved
The Scarlet Letter. But I have to say that it deals with some difficult themes and concepts and has a very particular mindset... It certainly wouldn't be something I'd recommend to a high school student (I read it at year 3 at the university).
Back to the 20th century... You can't go wrong with
To Kill a Mockingbird when it comes to rather simple English language, and it's not a difficult book to understand on any level, but it's still good. I also second
The Lord of The Flies, but that one is... well, considerably darker. Aldous Huxley's
Brave New World is a good book, but I prefer
Point Counterpoint by the same author, it's richer and presents many of his ideas in more depth (though that one is not SF at all, while
Brave New World is). I must say I wasn't all that impressed by
The Catcher in the Rye... I wonder if that was because I was 22 when I read it and was already past the teen angst stage in my life. Maybe I would have related to it better when I was a teenager... we'll never know.
On the other hand, an author you should
avoid before your command of English is excellent is William Faulkner - he tends to intentionally use some... odd styles and language constructions in his works.
As for SF - try something by Ursula LeGuin; how about
The Left Hand of Darkness. And I most definitely recommend anything written bu Kurt Vonnegut, whether it falls into SF (
Slaughterhouse Five, Cat's Cradle, Galapagos), has nothing to do with SF at all (
Mother Night) or falls somewhere in between (
The Breakfast of Champions); the distinctions are irrelevant in his case, he was a unique author with a very specific style, themes,narrative structures, and worldview. And he's not difficult to read at all, even you have only basic English skills, so you really must give him a try.