Christoph Waltz - Inglorious B's. The opening scene was a work of art, i was literally holding my breath and not making a sound, just like the family in the basement.
Ralph Fiennes - Schindler's List.
Freddy Kruger - original Elm St, the rest got progressively worse. But when the movie first dropped in the 80's, terrifying.
Nurse Ratched - as with Fiennes, the actor made you hate the character so much, that's talent.
Anton Chigurh - No Country for Old Men. Watched this recently, a cold, relentless, psychotic individual.
Heath Ledger - Joker. Amazing performance.
Lector/Buffalo Bill, Silence of the Lambs
Norman Stansfield, Leon. Fantastic performance from Oldman.
Alan Rickman, Die Hard. Really fun watching him play this character.
Original Predator/Terminator.
The Thing alien - terrified me as a kid.
The Xenomorph
Pennywise
Vader
Alex Forrest - Fatal Attraction. Glenn Close was bat **** crazy. Really put me off trying to get my end wet for a little while. Don't put your dick in crazy.
Shark, Jaws. Put me off swimming in the open sea for life
Annie Wilkes, Misery - holy cow!
Emperor Commodus - Gladiator.
Amy Dunne in Gone Girl was very good. The first time reveal was, "wow!"