I was coming in here to nominate Robert Knepper! His villains are the most convincing ever for me.
Blackadder is many things but he’s not actually evil. Cunning, conniving, weaselly, and even deceitful - but not actually evil.
Sorry! 
I disagree. He just did whatever he thought was best … for him.
Whoever it was who played the scumbag detective in Natural Born Killer. Ewww.
Same guy who was the sergeant in Searching for Private Ryan.
I think in reality he is a pretty violent man, in trouble with the law.
Slight correction: Although Gozzi,the armorer (Cyril Cusack’s character in The Day of The Jackal) was perhaps amoral, he certainly wasn’t the villain of the piece. Nor did he radiate much villainy in his role.
My choices would be:
Orson Welles in either The Third Man or Touch of Evil.
Robert Ryan in ***Crossfire ***or A Bad Day at Black Rock.
Ian Richardson in House of Cards and To Play the King, although not so much in The Final Cut as that series had a rather perfunctory tone to it.
Michael Gambon in 2004’s Layer Cake.
Burt Lancaster in The Sweet Smell of Success
**Henry Fonda **in Once Upon a Time in the West
That would be Tom Sizemore. He’s had some highly publicized issues with drug arrests, though I haven’t seen anything related to violence.
Mads Mikkelson (may have misspelled) really commits to playing a villain when he does as in Casino Royale & Hannibal. It’s esp obvious when you see him play a ‘normal’ guy in other roles
Old thread but I’ll jump in. My suggestion would be Jack Carter (Michael Caine) in Get Carter. And unusually, he’s the protagonist of the movie - he’s not just a villain the hero is opposing.
Carter treats the people around him like shit. He treated his brother like shit. But somebody killed his brother so he wants revenge. It’s not due to a belated feeling of filial affection - he’s mad because he sees his brother being killed as an act against him. So he goes out to kill the people responsible - and several other people along the way - with no regard for the consequences of his actions.
Andrew Scott as Jim Moriarty in Sherlock.
StG
As long as this thread is active again, I should mention one I forgot, a performance that stands as truly holding nothing back in order to present us with a scary, twisted, complete madman: Ben Kingsley as Don Logan in 2000’s Sexy Beast.
I agree with all of these.
And Orson Welles in The Stranger
Even more so than Anthony Hopkins - Ted Levine, who played Jame Gumb a/k/a Buffalo Bill, the serial killer. He was far more terrifying in his own way than Hopkins. Lecter was a controlled insanity of sorts. Gumb wasn’t.
Awww, I got here late and most of my picks have already been mentioned. I can add a few comments, though, if that’s okay:
William H. Macy in Fargo (post 33). This may be the winner, for the reasons stated.
Laurence Olivier in Marathon Man (post 36). And in Sleuth with Michael Caine.
Robert Mitchum in Cape Fear (post 42) and Night of the Hunter (post 89). Evil right down to that swagger and snide drawl.
Sam Rockwell as The Green Mile’s ‘Wild Bill’ Wharton (post 68). You could practically smell his filth.
Lee van Cleef in The Good, the Bad, and the Ugly (post 77). This performance made the biggest impression on me, but RickJay has made a pretty good case for William H. Macy in Fargo (post 33).
F. Murray Abraham in The Name of the Rose (post 87). IIRC, the impact is heightened by the fact that in the first few minutes that we see him onscreen, he’s turned away from the camera. I’m no expert on films or acting, but I thought it was a brilliant device.
Ted Levine in Silence of the Lambs (post 93): That freaked me right the hell out!
Bridget Fonda in A Simple Plan (post 100). Excellent choice. The bangs down to her eyes made her seem all the more scheming and cynical, for some reason.
Orson Welles in The Stranger (post 113). There’s a scene in which he lies and it’s supposed to be very obvious that he’s lying. Again, I’m no expert on films or acting, but I thought it was very well done.
My contributions:
Robert Shaw as Doyle Lonnegan in The Sting.
John Vernon as Dean Vernon Wormer in Animal House.
Bob Gunton as Warden Norton in The Shankshaw Redemption.
Jonathan Banks as Zack (the bad guy’s main henchman) in Beverly Hills Cop. Looked mean as hell. What a surprise to see him as Jay’s brother Donnie in Modern Family.
Richard Dreyfuss as Dr. Leo Marvin in What About Bob?
Colin Cunningham as Detective Brian Curtis in the Canadian TV series Da Vinci’s Inquest. Sliiii-my!
I’ll second Henry Fonda in Once Upon A Time in the West. I’ve never seen eyes quite so cold.
The first time I saw Ray Liotta was in Wild Thing, and he just radiated pure menace. Best thing about that movie.
Stellan Skarsgård and Jonathan Pryce from Ronin are both cold bastards, but then pretty much all the main characters are as well.
Yes! to this.
Peter Lorre in “M”.
Gotta give a nod to Michael Gambon playing Albert Spica in The Cook, thief, his Wife and her Lover. He was one of the vilest villains from scene one and he plays him as unlikable all the way through. I’ve never wanted to see a character get what he deserves more than ole Albert and the movie doesn’t really skimp on it.
Helena Bonham Carter really nailed the part of Bellatrix Lestrange in the “Harry Potter” series. Bellatrix was a total sociopath in the books, and Bonham Carter was absolutely perfect. Even that whole gleeful, enthusiastic way she had when she was tormenting someone.
Margaret Hamilton who played the Wicked Witch of the West in “The Wizard of Oz”. She said small children were always scared of her after that, which bothered her, since she had been a teacher. She’d always have to explain that she had only been playing a role in a movie.