I noticed someone mentioned Frankenstein before. I read it for the first time about a year ago. I didn't think I'd like it, but it took me in and held me cover to cover, I cried more than once. What surprised me is that there was nothing frightening about this story.
On the other hand, the same day I downloaded Frankenstein (by the way these are all originals) I got Dracula. Now that one gave me the willies that stayed with me for months! I absolutely could not get past 1/4 of the book, not because of the writing - which was so excellent I went back to study some of the sentence structure in the earliest chapters, and I studied how the book is put together - but the content was simply horrifying. And there was absolutely nothing violent, no blood, no bodies, but there was creepiness around every corner. My blood pressure was so high after reading one passage I had to take extra aspirin!
Once of my favorite authors, who I started reading on my own in the fifth grade, is Alexander Dumas. One of my favorite books growing up, besides Robin Hood and The Three Musketeers, was The Canterbury Tales.