I like Heart of Darkness too but there is valid criticism. You should read Chinua Achebe’s An Image of Africa, a lecture that set off the criticism of this book. It’s not a bad book by any means and it is a product of its time but the criticism too is valid. I would not rate it a zero by any means.

The Alchemist by Paolo Coelho. This book appears on so many lists for being profound and spiritual but I found it to be utter pseudo-spiritual new age crap. The writing is also atrocious.