This is very strange. RetroComedy has assembled their catalog of the 15 creepiest ads of all time. I'm thinking they've done a good job.
My faves are 15, 14, 6, 2, and 1. You have to click on the #6 ad and read the text and see what they're really pitching. I vaguely remember ads along these lines for Lysol in the past, but the reality is so much creepier.
(Thanks to Herb for pointing this out to me.)