When people ask me how I managed to write a character as evil and twisted as The Babydoll Strangler in my romantic suspense novel The First Victim, I tell them it was easy.
The rules that govern polite society don't apply to villains. They are scheming, ruthless, narcissistic, soulless predators who think they're above the law. These cruel, malevolent sociopaths enjoy frightening and hurting their prey. They're fun to write. They're even more fun to read!
I'm a huge fan of authors who can create the kind of bad guys (or gals!) that have me checking to make sure I've locked the doors. My favorite villains and their creators include:
Arthur Conan Doyle's Moriarty
Patricia Highsmith's Tom Ripley

Ed McBain's The Deaf Man
Daphne Du Maurier's Mrs. Danvers
Thomas Harris' Hannibal Lecter

James Patterson's Cassanova
Stephen King's Pennywise
JK Rowling's Voldemort

All of these villains wield fear as their weapon of choice. Some with charm. Some with violence. All with surgical precision.
The authors who created them have branded these characters in my imagination with the kind of skill that leaves me both jealous and amazed.
How do you feel about villains? Love 'em? Hate 'em? Or love to hate them? Which ones are the ones you can't forget (even if you wanted to)?