Not many of the so-called classics actually stand the test of time. Most lose their luster over the years. Not because they weren't good, but because the style of production evolves and audience taste changes.
While you can expect to see many classics on the typical 100 Best Books Ever list, compiled by whoever, it's often due to nostalgia, or more likely, what I like to call 'The Emperor's New Clothes' effect ie: people vote for a classic, rather than their true favorite, possibly because they think it makes them appear more wisdomous, or perhaps because they don't like to go against the crowd.
I'm happy to say that, for me at least, Pride and Prejudice thoroughly deserves its good reputation. Sure the language and narrative style has changed over the last couple of hundred years, but the story works just as well now as it ever did, and the characters are wonderful! My favorite by far was Mrs. Bennet. Her reaction on learning of Elizabeth and D'Arcy's engagement made me LoL out loud.
How about you?
What do you think of the book you're reading at the moment?