Which book do you refuse to get rid of?

For me, it's Blood Meridian. I've never in my life read anything like it before and will probably never read anything as visceral, and haunting like it again. It is the most fascinating book that has ever horrified me. I want my children to read it.

What do you think about it? Do you hate the protagonist? Did Judge Holden terrify you? Do you wonder how the protagonist could ever redeem himself? Were their murderous escapades enchanting to you?