to be honest, i'm more of a mystery person rather than a horror person, but my favorite horror book is the original Frankenstein by Mary Shelley. Besides that, there are a bunch of horror stories that are published on the internet that have given me a good scare. one that i remember a ton is probably Ted the Caver, which i'm pretty sure was a creepy pasta. if you haven't read it, i totally recommend. for mystery, i recommend And Then There Were None by Agatha Christie. it's a little confusing at first (mostly due to the amount of people), but as it keeps going it's absolutely thrilling. :)