Here is a wonderful collection of horror comic book covers ranging from the 1950's through the 1970's.

It is just a delightful display of devious and macabre imagery that was mostly drawn during the Pre-Code era, when comics weren't regulated by the Comics Code Authority. There were still able to get away with some stuff after comic books became regulated, but not quite as diabolical as before. Check out this great collection of horror comic cover art.