Khan from Star Trek Wrath of Khan.
The Skeksis from the Dark Crystal.
The late Alan Rickman in Robin Hood Prince of Thieves as the Sheriff of Nottingham.
Good one!
Nick Bockwinkel, The Mongolian Stomper, and Ron “Motormouth” Wright.
Alan Rickman in “Die Hard.”
Philip Seymour Hoffman in “Mission Impossible 3”
I second Ricardo Montalban in "Wrath of Khan.
Count Rugen
“And remember, this is for science so please - be honest”
HAL in 2001. So subtle and polite.
Christopher Waltz in Inglorious Basterds was an excellent villain as Col. Hans Landa.
Cercies Lanister in Game of Thrones was a great villain as well.
Lalo from Better Call Saul.
Todd from Breaking Bad—a stone-cold sociopath who doesn’t even know he’s a villain.
Clarence Boddicker in Robocop. “Well, I guess we’re gonna be friends after all … Richard.”
Frank Underwood from House of Cards.
Boss Jim Gettys in Citizen Kane. “I’m not a gentleman. I don’t even know what a gentleman is.”
Brian Donlevy as Sergeant Markoff in the 1939 version of Beau Geste
The entire supporting cast of The Maltese Falcon
Douglas Fairbanks, Jr., as Rupert of Hentzau in the 1937 version of The Prisoner of Zenda. In the 1952 version, James Mason is a better actor, but I don’t think he was quite right for the role.
Raul Julia as M. Bison in Streetfighter. He knew it was a silly, over-the-top role, and he chewed the scenery til it screamed.
Count Baltar in the original Battlestar Galactica. The writers wanted to give him more depth than ended up onscreen.
King Richard III in the Shakespeare play. Laurence Olivier and Ian McKellen both did well with it.
Moishe in Unorthodox, I find him strangely compelling as his sect’s fix it guy.
Alan Bates as the extremely creepy stranger in The Shout
John Lithgow as Emilio Lizardo in Buckaroo Banzai
This is a bit obscure but … Gatehouse from the BBC thriller The Shadow Line. A polite, civilised, sympathetic stone-cold psychopath. (And I didn’t even really like the show all that much by the end - but they had some phenomenal villians)
Less obscure but slightly out of left field: Lady Catherine de Burgh. Now there’s a woman who knows exactly what she wants
Anton Chigurh from No Country For Old Men. Completely implacable.
Gus Fring from Breaking Bad (but that’s a tough show to pick a villain since the protaganist is the worst one of all.)
Negan from The Walking Dead
Barnes, from Platoon.
Hans Gruber, Die Hard
Malcolm McDowell
Rudolf Klein-Rogge as Dr. Mabuse in Dr. Mabuse the Gambler (1922) and The Testament of Dr. Mabuse (1933)
Charles Laughton as Dr. Moreau in Island of Lost Souls (1932)
Walter Huston as “Dead Legs” Flint in Kongo (1932) - preceded by Lon Chaney, Sr. as Phroso in West of Zanzibar (1928)
Boris Karloff as Hjalmar Poelzig in The Black Cat (1934)
Walter Slezak as U-boat captain Willi in Lifeboat (1943)
George Macready as Ballin Mundson in Gilda (1946)
Orson Welles as Harry Lime in The Third Man (1949) and as Cesare Borgia in Prince of Foxes (1949)
Robert Mitchum as Harry Powell in Night of the Hunter (1955) and as Max Cady in Cape Fear (1962)
Gian Maria Volontè as Ramon in A Fistful of Dollars (1964) - preceded by Tatsuya Nakadai as Unosuke in Yojimbo (1961)
Tatsuya Nakadai as Ryunosuke Tsukue in The Sword of Doom (1966)
Henry Fonda as Frank in Once Upon a Time in the West (1969)
Cesar Romero as Dr. Malic in Latitude Zero (1969)
Eric P. Caspar as Charlie Umlaut (“My name is Charlie Umlaut and I’m going to kill everybody now.”) in Dead Pigeon on Beethoven Street (1973)
Brigitte Lin as Master Asia in Swordsman II (1992)
Robert Patrick had an impossible challenge in TERMINATOR 2 and still hit it out of the park.
Also Lee Van Cleef in “The Good, The Bad And The Ugly”.
I like Blake Edwards’ over-the-top villians:
Jack Lemmon as Professor Fate
Herbert Lom as Chief Inspector Dreyfus