He was wonderful (and villainous) in Bleak House.
“Shot them, shot them both”
“Fraulein, let me show you what I am used to dealing with”
“Hiel Hitler”
“You Americans are all the same. Always overdressing for the wrong occasion.”
Toht, from Raiders of the Lost Ark.
The man is pure evil. The way he starts to almost giggle when he is about to torture someone, he freaks you out with his travel hanger. He even looks over the top of a magazine with pure menace.
But my favorite thing is near the end when Indy appears with the Panzerfaust and threatens to blow up the Ark. Everyone generally panics or such and Toth just sort of sighs and sits down because it’s too hot for this BS.
But my all time favorite is Nurse Ratchet from One Flew Over the Cuckoo’s Nest. She is just pure evil. She even defeats Jack Nickolson!
“The Operative,” from the Firefly spin-off movie Serenity.
I know Firefly and Serenity get mad love here on the board; I know because some of it comes from me. 
But to the greater public, they’re both less well known, and thus less appreciated.
Philip Seymour Hoffman as Owen Davian in Mission Impossible 3.
A sleazy mean bad-ass. I really wish he would have saved this character and used it as a non-literal penguin for the third Batman installment opposite Christian Bale.
He ain’t lucky, though.
Billy Zane plays incredible bad guys- honestly, I don’t understand why he doesn’t get more work.
I loved him in Demon Knight, as the Collector.
"Has anyone ever told you how beautiful you are? I know that sounds like a line - Lord knows I’ve used it - but I mean it. "
I liked the quietly menacing Frank Nitti, played by Stanley Tucci, in* Road to Perdition*, myself.
The best “Nixon” I’ve ever seen was the Charles Logan character on 24.
I, too, sound like a broken record, but IMO nothing on celluloid beats Ben “Gandhi” Kingsley playing “Don Logan” in Sexy Beast.
More unpleasantness here. If you’ve never seen this movie, watch it. It’s not the best movie ever per se, but it’s a fantastic ensemble piece, with an awesome script, and Don Logan is absolutely the most horrendous sociopath ever. (Apparently Kingsley based the character on his grandmother…!)
I think Kiefer plays some of the best villains - my personal fave is Robert Doob from Eye for an Eye -
quotes -
(meeting up with the Mother of one of his victims, who he raped and killed) -
Robert Doob: What? You want me to say I’m sorry? It could have been anybody. I don’t even remember what she looked like. It’s nothing personal.
Karen McCann: She was seventeen years old. She was five-foot two. She had brown eyes. Her name was Julie. She was my daughter.
Robert Doob: She was a great fuck.
(Threatening the Mom’s youngest daughter, who seems about four or five)
Robert Doob: You know I really don’t like Kiddy pussy, but I’m willing to make an exception.
(Leaving the courtroom after getting off on a technicality - the victim, Julie, had a pronounced stutter - )
Robert Doob: [when leaving courtroom, to Karen] S-s-s-sorry.
Paul’s Grandfather.
.
I agree completely!!!
That character was scary as hell. Guys like that really exist and the only way to deal with them is what they did in the movie.
That truly was one of the finest acting jobs I have ever seen.
Kingsley played Ghandi and then that freak. Now that is range.
The Creeper himself…Rondo Hatton.
Tom Berenger as Barnes in Platoon.
I’m not even sure if he counts as a “villain,” but he was certainly a brutal, complex, and possibly evil character. The sequence in the village and the last few scenes with Elias and Barnes were stone cold.
DeNiro as Max Cady in Cape Fear.
Sleazy and seemingly idiotic, yet smart enough to find the perfect way to subtlely terrify his victim psychologically. The part where he charms Nick Nolte’s daughter is a great example.
How about Tilda Swinton as the Angel Gabriel in Constantine?
Ian Howe in National Treasure. He wanted what he wanted, but he was not malicious about it in any way. He didn’t want to hurt people for the sake of hurting them. He was not gratuitously violent. He just did what he needed to do to accomplish his goal.
The Operative: I’m sorry. If your quarry goes to ground, leave no ground to go to. You should have taken my offer. Or did you think none of this was your fault?
Capt. Malcolm Reynolds: I don’t murder children.
The Operative: I do. If I have to.
Capt. Malcolm Reynolds: Why? Do you even know why they sent you?
The Operative: It’s not my place to ask. I believe in something greater than myself. A better world. A world without sin.
Capt. Malcolm Reynolds: So me and mine gotta lay down and die… so you can live in your better world?
The Operative: I’m not going to live there. There’s no place for me there… any more than there is for you. Malcolm… I’m a monster.What I do is evil. I have no illusions about it, but it must be done.
I’ve never seen that version, but you reminded me of Robert Mitchum in the original Cape Fear. He was my first exposure to a charming, sexy psychopath, and oh my, I was repulsed by him and hot for him at the same time. It didn’t matter that I was too young to know what the “hotness” was all about, I eventually figured it out. My parents never would have let me watch it on TV if they’d known what was going on inside my mind and body. At least it didn’t warp me. I was never attracted to bad boys because of it.
Robert Mitchum…sigh.
Dolph Lundgren as Scott/GR13 in Universal Soldier.
Your basic crazy zombie/cyborg/whatever/super-soldier. But I think the best part is that I couldn’t tell if the actor or the character was having a better time being a villain.
Just such pure, almost childlike joy combined with being an utterly badass sadist. And a habit of wearing parts of people’s heads in a charm necklace. Almost like a proto-Joker. 
I didn’t see “Constantine”, but Swinton was deliciously, fiendishly evil as the White Witch in “the Lion, the Witch & the Wardrobe.”
A personal favorite: Frank Langella as Dawg Brown in Cutthroat Island. IMDb recalls this line:
Pirate: We can’t leave yet, Captain. We haven’t put enough food on board.
Dawg Brown: We need less mouths. [Shoots Pirate]