Frankenstein

Hm. Definitely one of the most interesting classics I've read so far. I was pretty much never bored, you know, it was really well paced.
Um... but it was also just deeply unsatisfying. I think I had too much sympathy going both sides and somehow that ended with me feeling that the ending was not tragic enough for either of the two sides.
Also, just don't end your story with the villain monologuing why they did what they did. A bad idea. That actually WAS boring. Don't do that, it is awful. The end.