sniffles said:
Tilda Swinton. She played an angel in "Constantine", and the White Queen in the upcoming Narnia film, and she even played an gender-changing immortal in "Orlando".
That's why she looked so familiar in the trailer! Yeah, I remember
Orlando: "The treachery of women." And several centuries later, "The treachery of men."
Spookiest actress:
I think you have to go with someone who has multiple performances that fit the bill. On that count, Bette Davis (
The Nanny,
Watcher in the Woods,
Whatever Happened to Baby Jane?,
Hush, Hush, Sweet Charlotte,
Wicked Stepmother--hmmmm, her "W" films are her creepiest!) and Christina Ricci (
Addams Family,
Addams Family Values,
Sleep Hollow,
Bless the Child, etc.) are certainly front-runners.
Jane Badler is a one-trick pony, so she don't count!
One friend of mine doesn't like Shelly Duval, but her only really creepy role is
The Shining (and she's not really the creepy one in that movie). Well, and maybe
Popeye.
Olivia Newton-John and Stockard Channing and most of the "Pink Ladies" give me the creeps in
Grease, but that's because they were 30 years old playing teen-agers.
Certainly, Margaret Hamilton could be a contender--those 1970s Maxwell House commercials rivaled her creepiness as the witch in
The Wizard of Oz!

More seriously, Miss Gulch is almost creepier than the witch in
TWoO.
Of the ones mentioned in this thread, I think I'd vote for Bette Davis. With Margot Kidder as runner up (
Sisters, anyone?)