Romeo and Juliet | William Shakespeare
Poetry to die for
I always thought that everybody but me knew this story. It's hard to escape: It's sometimes assigned in school, the play is still performed in theatres, there's film adaptations in close keeping to the text like Romeo and Juliet (1968), and those taking some… creative liberties like Gnomeo & Juliet (2011). That's why I was quite surprised when I learned that a couple of my friends didn't even know that the two titular lovers commit suicide at the end—which is already revealed in verse 6, so don't you worry about spoilers.
But even if you know the basic plot of this tragedy and have seen a few adaptations, you'll probably still be surprised to find some plot details that are commonly changed or omitted.
And yet, the plot is not the main selling point of this play, the language is. The text is so full of puns, double entendres, and otherwise witty usage of words, that it's a real joy to read. Shakespeare's English is a bit difficult to understand for the modern reader, so I'd definitely recommend getting an annotated version that can help understand the text in all its meanings—I was happy with my copy, annotated by Burton Raffel.