Most viewers saw Col. Quaritch in Avatar as this, probably against James Cameron's intentions. The guy will do everything in his power to keep the people under his charge alive and safe (and his men obviously adore him for that), and he seems to be a fairly nice -if strict- person to have around... as long as you are not a Na'vi or a human who likes the Na'vi. It's telling that he actually got Jake a ticket home and a new set of legs for his efforts.
The main character Ben in Man Bites Dog. Sure, he's a Serial Killer who kills randomly, but he really is nice to his friends, inviting them to the restaurant and offering to help cover the costs of the movie.
Ditto for Iron Monger/Obadiah Stane in Iron Man, especially in the scene where he's talking to Pepper Potts. He's as affable as always, but she doesn't know whether he's just making small talk or interrogating her.
This continues into Iron Man 2 with Ivan Vanko. In battle, Vanko lets his rage and vengeance run wild, but in the few brief conversations he has with his nemesis, Tony Stark, he is measured and almost friendly, bantering and taking technical advice from Tony, who he likely sees as a Worthy Opponent.
Iron Man 3: Trevor Salttery, the "fake" Mandarin, is actually pretty nice, despite being completely oblivious to the machinations of the true villain, Aldrich Killian.
Frank Lucas from American Gangster is a very polite, well-dressed man who cares deeply for his family and takes his mother to church every Sunday. Despite this, he is frequently shown to have no qualms about gunning down people who get in his way in cold blood, or blighting communities with heroin for pure profit.
Arthur Burns of The Proposition is erudite and exceptionally loyal to his friends and family. He appreciates poetry, and is very supportive and patient with his underlings. Arthur also bashes policemen's skulls in with rocks, advocates gangrape, and burns entire families to death. It helps that he's borderline insane.
Bill from the Kill Bill movies is very friendly and likable, as well as a loving father, despite being a self-proclaimed "murdering bastard," and helps the Bride reach an epiphany about herself at the end of the duology.
He also genuinely cares for, and loves, The Bride. He's only trying to kill her because she broke his heart.
The Brain, from Gremlins 2: The New Batch. An erudite, genetically-altered gremlin who merely wants what everyone wants, and what you tropers have: Civilization! The Geneva Convention, chamber music, Susan Sontag...
The Nome King from Return to Oz displays a disturbing mix of affability and subtle condescension towards Dorothy and her friends (his counterpart in the books, though, was more of a cackling Card-Carrying Villain). The film Return to Oz plays the same "all a dream" card that the film of The Wizard of Oz played, and the Nome King, in this case, is supposed to be a direct analogue to the psychiatrist running the asylum where Dorothy is being treated at the beginning of the film. He himself is quite Affably Evil in his own right, warmheartedly declaring that electroshock therapy is "just the thing to cheer Dorothy up", words that the Nome King repeats later in the film.
Robert De Niro as Al Capone in The Untouchables: a Magnificent Bastard who goes from pontificating on the joys of baseball one second to savagely murdering an associate with a bat the next. Every word that passes his lips is met by sycophantic laughter.
Subverted in Shutter Island, where we are led to believe that Dr. Cawley is like this. As it turns out, this is his genuine personality, and, in fact, he has been running a very elaborate simulation in order to snap Teddy Daniels (real name: Andrew Laeddis) out of his self-induced fantasy that he is a Federal Marshall, in order to make him come to terms with his wife's death.
The Operative of Serenity is a man who is convinced of the righteousness of his actions, and holds no particular ill will for his enemies. Indeed, he goes so far as to compliment his foes' tenacity, bravery, or the good work they've done, even when he's impaled them on his sword and watching them die. Even more so is how he kills certain people with the sword. He paralyzes them, then lets them fall on it because he believes it's an honorable way to die. He's also willing to kill innocent civilians (including children and clergy), not because they stood in his way or had something he needed, but just to make sure his target has nobody to hide them. To his credit, despite his sincere belief in the necessity of his evil actions, he knows he is a monster with no place in the paradise he is trying to create.
The Operative: There is no shame in this. This is a good death, for a man who has done fine works.
The novelization claims that the Operative knew full well that Sheppard Book wasn't just a clergyman.
The books take this to a whole new level with characters like Marc-Ange Draco. Apparently, you can be guilty of drug-running, extortion, and murder, and effectively be a good guy as long as you're really, really nice and charismatic in personality.
Goldfingeris this trope. Is that mint julep tart enough for you, Mr. Bond? It is? Excellent. Now, going back to my scheme to nerve gas and nuke 60,000 people...
Never Say Never Again is an independently-produced remake of Thunderball featuring Klaus Maria Brandauer as an utterly charming version of Maximilian Largo. Shame about the psychosis lurking just under the easy-going, good-humoured facade...
In Rustlers Rhapsody, the villains realize that the hero, Tom Berenger, always beats "bad guys," so they hire a "good guy" to fight him. The "good guy" appears to be an even nicer person than Berenger and gains the upper hand, but Berenger soon learns that he's actually a lawyer, and is then able to defeat him.
Harry Lime from The Third Man is an early example, with Orson Welles receiving a lot of attention at the time for portraying the Manipulative Bastard as just a regular guy who wanted his old friend to like him even after discovering his actions.
While his underlings are quite rude, Xerxes in 300 is quite friendly — perhaps overlyso. Even at the moment of his triumph, he takes the time to congratulate Leonidas and offer the entirety of Greece to him, as long as he acknowledges the pecking order. Unfortunately, we don't get to see how affable he is after Leonidas breaks his Dissonant Serenity.
Ben Wade in 3:10 to Yuma is the very definition of affability and charisma.
In Lucky Number Slevin, both villains were Affably Evil, but The Rabbi especially. He even, ultimately, seems to genuinely believe the main character's assurances that he is not the person they think he is, and sympathizes with his plight.
So Affably Evil, in fact, that until the very last scene, you would never guess that he was the villain all along, making this the last truly shocking M. Knight Shyamalan twist.
The eponymous Serial Killer from The Stepfather series of films is fond of stuff like dogs, model building, and gardening; he's actually a pretty nice guy, at least, until things stop going his way. There's a scene in the second movie where he sits down to breakfast and only starts eating after his Rice Krispies pop; he looks as giddy as a kid when they make their trademark noise.
Angela Baker of the Sleepaway Camp series practically becomes some kind of murderous Genki Girl in the second and third films. She also really likes the "Happy Camper" song, and often honestly doesn't seem to understand why her victims are scared of her.
Bill The Butcher from Gangs of New York. He's polite, has a moral code, a deep sense of honor...but he just hates those bloody Irishmen invading American soil, and God help you if you get into a knife fight with him. To the point where Amsterdam is conflicted because he finds himself liking the man he intends to take revenge on for killing his father. He does have a few Kick the Dog moments where you realize the guy is not merely a Memetic Badass but pretty reprehensible, so the audience is conflicted too.
At least initially, Wikus in District 9 in several ways; he's an amiable, well-liked low-level functionary...who is casually racist and brutal towards the oppressed aliens, and laughs and makes jokes when 'aborting' alien eggs.
Idi Amin is also this way in Raid on Entebbe. He mainly gives the impression of being a ridiculous popinjay though.
Probably because the real Idi Amin was noted for his 'big-grins and belly-laughs' sense of humor. It's just a pity his idea of fun revolved around testicle crushing, mass-murder and cannibalism, meaning said belly-laugh was the last thing a lot of his victims heard.
In his first scene he actively does his best to be the perfect guest to Monsieur LaPadite asking for permission to smoke, sit, ask questions of LaPadite, speak in English and also compliments the flavor of the milk he's given. Hans even shows his viewpoint on the Jews saying he doesn't like the propaganda against them.
"If the Jews were compared to an animal it would be the rat. I, however, don't see it as an insult. (brief pause) Consider the environment of a rat. It is undoubtedly dangerous and unfriendly yet they survive which I find rather inspiring."
It could be argued that Landa rather personifies the opposite trope, Faux Affably Evil. In every situation where he showcases his (extremely exaggerated) politeness and cheerful disposition, both he and his counterpart are perfectly aware that Landa is a clear and present danger. Landa is a master interrogator, and his prime technique is to put his victim in a number of most uncomfortable situations possible, all the while blocking the "escape" by behaving as if his companion is thoroughly enjoying the conversation. He pointedly ignores any non-verbal signs of distress from his victim, while forcing him or her to respond in kind - thus preventing any way of retreat, either polite or defiant. Should the victim try to break off the conversation, it would be the victim who transgressed - and that would sink him/her even deeper. Landa even pushes his method to the limits for his own enjoyment - such as when he laughs hysterically, mocking the explanation of von Hammersmark's broken leg (only to apologize a second later), or pours a round of wine, perfectly amiably and as a gesture of peace... to his handcuffed charges. In the latter case, he doesn't even have to savor the wine - quite the opposite, that would make him a petty villain; while the fact he didn't even touch his glass makes the gesture even more disconcerting. Not only his affable manner lets him drive the knife as deep as he wants - it allows him to utterly confuse his victim and make every new strike a complete surprise.
In another Tarantino movie, Django Unchained, Calvin Candie generally seems like a friendly and polite gentleman who epitomises Southern courtesy and hospitality, and has a genuinely friendly relationship with his head house slave, Steven. He also uses his slaves in savage (and lethal,) prize fights. In his Establishing Character Moment, he is overseeing one such brutal brawl to the death, but looks away from it to expansively invite Dr Schultz to join him (he doesn't stop the fight, it's still going on in the background, he just ignores it while greeting his guest), then when his slave wins he throws him a hammer and orders him to perform the Coup de Grāce on the broken and begging loser, and when he does so Candie promptly showers him with warm congratulations, gives him a drink and tells him (sincerely) to enjoy it.
However, when things don't go his way he becomes Faux Affably Evil; when his runaway slave D'Artagnan has been chased up a tree by the dogs, his affable demeanour never changes, and his tone of voice suggests wounded disappointment rather than real anger. However, as the conversation continues to the money he paid for D'Artagnan, he humiliates the broken slave in front of everyone by asking him if he knows what "reimburse" means. He then has him killed by being ripped apart by the dogs.
Actually, comparing Candie from when he is happy to when he isn't illustrates the difference between Affably Evil and Faux Affably Evil, possibly best exemplified when, after Steven exposes Django and Schultz's scheme he maintains his demeanour in a rather more sinister tone to put them on edge, before flipping into Chewing the Scenery-level anger and threat-making, and then alternating between the two states to scare everyone, during all of which he is never actually rude, and he never fails to use "mister" or "doctor" when addressing his fellow white men. His Evil Gloating after his victory also takes this form, as he offers Schultz dessert and cites Southern courtesy as the reason for his insisting that Schultz shake his hand, but here his courtesy is clearly for the purpose of rubbing his defeat in his face.
The Green Hornet: Benjamin Chudnofsky. He has a politeness and an inferiority complex that's pretty disarming, and he tries too hard to seem intimidating in the end, but is dangerous when people point out that he isn't 'scary'.
This character is played by Christoph Waltz, the same actor that portrayed the above-mentioned Hans Landa. Waltz rather excels at playing Affably Evil characters.
VIKI and the NS-5's from I, Robot. They are polite and calm while trying to take over the world.
(The normally loyal robot blocks Susan's way) Robot: Please remain calm. Robot: Please refrain from going to your windows or doors. Susan: Deactivate! Susan: Commence emergency shutdown! Robot: We are attempting to avoid human losses during this transition.
And later, before attempting to kill people
Robot: You have been deemed hazardous. Will you comply?
Major Koenig from Enemy at the Gates qualifies as this for much of the movie. Sure, he's out to kill his sniper counterpart, but he's polite about it, and when one character, a young boy acting as an informant, hears of his rival's supposed death and is trying not to cry:
Koenig: There's no shame in it. You're a Russian, like he is.
When he figures out that the kid's been informing on him to the Russians, instead of confronting him, he hands him a chocolate and gives the kid a Mercy Lead, telling him not to come back. The kid comes back, so Koenig hangs him from a telephone pole to use as bait to lure out the Russian sniper.
In Agora, there's hardly any completely maleficent villain; the Christians are, after all, still human, and while they were very fanatical and Knight Templar-ish, they still helped the poor and each other. In fact, the only person who was truly villainous was the Bishop, Cyril of Alexandria, who himself is very Affably Evil, caring for his people and all.
Swamp Thing from Con Air. He's such a jolly, good-humored sort that you almost forget that he's an integral part in a scheme to bust out a planeload of mass murderers, terrorists, and gangsters. You also tend to wonder what he did to get himself put on that plane in the first place.
Drug smuggling, but even his actor defends him, pointing out that he didn't kill anyone or get in their faces...
"Good Evening. Welcome to my humble abode. My, how beautiful you are. I hope you will stay the night. Oh, where are my manners? Allow me to introduce myself. I am Count Dracula."
A clearer example of Affably Evil in Star Wars is Count Dooku, at least in Attack of the Clones; he's clearly more respectful towards the Jedi than they are towards him.
Dooku: It's a great pity that our paths have never crossed before, Obi-Wan. Qui-Gon always spoke very highly of you. I wish he were still alive; I could use his help right now.
Obi-Wan: (With quiet fury) Qui-Gon Jinn would never join you.
Dooku might actually be Faux Affably Evil, slyly delivering the right amount of hints to Obi-Wan in order to plant the seed of division among the Jedi while painting himself as the good guy. Notice how his behavior in the scene he shares with Obi-Wan is very different to the way he behaves in any other moment of the movie or Revenge of the Sith. (Indeed, in the Sith novelization an extended section taken from his point of view has him musing, though not in such terms, that he's a sociopath.)
Hannibal Lecter of The Silence of the Lambs is an interesting example in that nobody can be really sure if his affability is just an act, particularly as he's prone to sniping insults at visitors who displease him. To credit the "affable" perspective, he never hunts down Clarice (considering such a thing "rude"), and, in the book, mails a substantial tip to an orderly he befriended - specifically, the orderly who ensured that Hannibal never escaped from the asylum until he was moved, and once broke Lecter's arm stopping him from attacking a nurse.
The example of the orderly lends evidence of being genuinely affable, since the very reason Hannibal liked him was because the orderly was always respectful, and never rude, even in the case where he broke Hannibal's arm. Hannibal sees a man who does his job, does it superbly, and does it in a way that lends what dignity he can to his charges. These are all things that Hannibal has been shown to admire.
The simple answer is that he is genuinely nice and respectful to people who are genuinely nice and respectful to him.
Dredger from the Sherlock Holmes movie is an extremely large thug who will wreck the place and crush you (with his bare hands, if necessary) if that's what he's been paid to do...but he's surprisingly personable about it.
The HBO movie Conspiracy is an extremely chilling example of this trope. A group of intelligent, cultivated, soft-spoken men having a secret conference in Germany in 1942 about what to do with the "storage problem" of the Jews in Europe. And it is based on the minutes of the actual meeting.
The brother and sister duo, Vincent and Ida, in Motel Hell. They are a hospitable couple who run a nice little motel and provide some great meat pastries which are made out of people.
Dr. Schaefer, The President's Analyst, ends up abducted by The Phone Company. Arlington Hewes, its president, is unfailingly pleasant and polite while he explains to Dr. Schaefer why he needs his professional knowledge for his world-domination plan — and while he inflicts high-tech torture on Schaefer when he refuses to help.
In The Imaginarium of Doctor Parnassus, the plot of the movie is set in motion when Mr. Nick (Tom Waits), having already won the soul of the Parnassus's daughter in a wager made decades before she was born, agrees to allow Parnassus to try to win it back on the eve of its forfeiture (even though Parnassus has absolutely nothing to offer to sweeten the pot). Throughout the course of the story, it becomes clear that Nick is deliberately trying to lose this wager to avoid ruining his Friendly Enemy status with Parnassus, to the point that he tries to physically restrain the daughter from deliberately damning herself to Hell just to spite her father and, when that fails and he wins the bet, he immediately offers Parnassus a new wager so he can try to win her back again.
This leads to one of the film's best lines: "Damn. I won."
Jules Winnfield in Pulp Fiction is actually a pretty nice guy, for a mob hitman. Just don't say "What?" to his questions. In fact, all of the gangsters in the film are affable and friendly, even when they're casually waving a gun in your general direction.
Big Jake has the villain, played by Richard Boone. He would be happy to have a nice, pleasant, friendly conversation with you...just before pulling out a gun and killing your children in cold blood without so much as flinching.
Lynch from The A-Team movie. He's just so adorable about being evil.
Lynch: We do have laws, they're just cooler than yours.
Charlie Barrett in Suicide Kings. The nicest guy who ever fed anyone to their own dogs.
Cheyenne in Once Upon a Time in the West is a cheerful, friendly fellow who seems perpetually amused by the events in which he is caught up. He's also a confessed murderer and bandit leader. It helps that A) he's not the villain of the film, just the local badman whose territory the villain trespasses on, and B) all of his crimes take place off-screen (just outside the door in the case of his slaughter of his prison escort).
Tuco of The Good, the Bad and the Ugly. He doesn't seem like such a bad guy, he's even pretty funny, but then you remember he's a criminal who isn't above the rape and murder of civilians, if you believe the list of crimes read by his executioners early in the film. One scene that helps is a brief conversation between Tuco and his brother, where we to get a few hints as to why he is who he is. It's implied that it was simply because he grew up in a poor family and the only way he could survive was to steal.
Juan from Duck, You Sucker! is initially set up as a mean, ruthless, and amoral bandit, then we get to know him and find out that he's just an ordinary guy trying to look out for his family in a world where stealing is the only way to survive.
Big Chris of Lock, Stock & Two Smoking Barrels is a hitman, but is overall a nice guy, and a good dad to his son, Little Chris. But so much as lay a finger on Little Chris, and the affable part goes out the window.
To some extent, Lyle From Dallas from Red Rock West. Protagonist Michael Williams first meets Lyle after nearly being run over by him - Lyle is very apologetic about it, makes sure he's okay, gives him a ride back to town, bonds with him over their shared past with the Marine Corps, and buys him a drink. Since this is the first we see him, his turning out to be the bad guy would almost be a twist, were it not for him getting very angry about Michael initially refusing his offer to buy him a drink, as well as the fact that he's played by Dennis Hopper.
The villain in Babysitter Wanted chats merrily with the final girl as he's carving up the body of another girl. His accomplice later gets mad at him for being so friendly.
Colonel Hepburn from the Hammer Horror film, Cash On Demand, is a friendly and amiable man. When he visits a bank, he is more friendly to the employees, and knows more about them personally, than the bank manager does. The reason he's visiting the bank is to rob it...
Lex Luthor is played like this in the Superman films, especially by Gene Hackman, with a warm smile and a nice disposition. Yet he's willing to sink California to the bottom of the sea for profit.
All the villains in Alfred Hitchcock's Saboteur. In between planning and executing acts of sabotage against military installations, we see a kindly grand-father playing with his grand-child, a rich socialite who hosts a charity-dinner, a father who ponders whether he should let his son have long hair, a man who gives their hostage a milkshake, and a man who frets that the confrontation with the hero will make him unable to go to the philharmonica with his niece later that evening.
As in the novel on which the film is based, Don Vito Corleone from The Godfather. Warmhearted, reasonable, prefers to think of his partners as "friends", and happy to perform the odd favour for his less-than-fortunate neighbours. True, he does inform them that they might have to do a little something for him in return, but contrary to Amerigo Bonasera's worries, all he usually asks for is a free service from their business. He even adopted Tom Hagen and eventually allowed him to become his personal advisor - even though he knew that none of the other Mafia bosses would approve. Vito's still in charge of one of the most powerful Mafia families in America, and he's not above the occasional murder or extortion to back up the usual income from gambling and union racketeering. However, Even Evil Has Standards, which Vito demonstrates in his refusal to deal in drugs and prostitution (the most contemptuous line in the film is when he says, "Tattaglia's a pimp"). And, to his credit, he does his best to keep his children and his civilian friends as far away from crime as possible.
Having learned from his father, it's unsurprising that Don Michael also fits this trope; however, though well-mannered and gracious, he lacks Vito's degree of warmth - which, combined with his ruthlessness, eventually begins to distance him from his friends and family.
CLU from TRON: Legacy. He is completely affable and polite with Sam from the beginning, and his personal moments of violence always appear to be casual afterthoughts, as in when he is blowing up the End of Line Club, or yelling and slamming his hands into the table at Kevin Flynn's home, making something of a mess, or de-rezzing Jarvis after a last-straw moment of incompetence after a long string of mild-to-major failures. The rest of the time, he is cool, calm and collected, and polite. After all, his most oddly polite line to Sam is "So, you like bikes." complete with a pleasant smile.
Julian Karswell from Night of the Demon is charming, charismatic, pleasant, loves his mother, hosts parties for local children...and is a Satan-worshiping cult leader who uses black magic to kill casual acquaintances.
Elizabeth Hurley as Satan in the 2000 remake of Bedazzled. She's out for Elliot's soul, but she generally acts friendly and sympathetic to him most of the time. Even after he nullifies their contract and saves himself, she stays polite and cordial before seeing him off. Actually a subversion, since the end of the film reveals that she's not evil at all.
John, one of the main antagonists in Drunken Master 2, is some form of this. He's very cheerful for almost the entire film, except when being brow-beaten by the British Ambassador he's working for, and when Fei-Hong is beating the crap out of him at the end of the film. He even gives a cheery thumbs-up and a big grin after kicking Fei-Hong onto burning coals.
Mr. Bentley (played by Patrick Stewart), the villain of Masterminds, is charming, polite, levelheaded, and witty. He also equips his men with Instant Sedation dart guns during the initial takeover of the school and orders them not to injure anyone while repelling the cops' attempts to retake it (although it's really only through the magic of Hollywood ballistics that no one is killed).
Professor Henry Jarrod, as played by Vincent Price in "House of Wax (1953)", is a genuinely kind person. The Professor is constantly polite, he never mistreats his deaf/mute assistant (actually named Igor), compliments the ladies for their beauty, and goes to great lengths to save them from pain and horror while he transforms them into detailed wax figures.
Debatable example, as he isn't evil so much as completely out of his mind.
How can you not fall in love with Slim Pickens' character Taggart in Blazing Saddles? He's an evil racist who goes along with every evil scheme devised by the film's Big Bad, but there's something about Slim Pickens' accent that causes him to steal the show every scene he's in. He even gets a Crowning Moment Of Awesome towards the end with this classic line:
Bane from The Dark Knight Rises always sounds calm, polite, and friendly... even when he's crushing your skull.
Dr. Evil from Austin Powers, much like the villains from 'James Bond', invites Austin into his lair, makes him a meal and designs tailor-made futuristic clothes for him and his love interest to wear.
Taken to an even higher level in the third movie where, in the final act, they team up to take on the secondary antagonist of the film.
Richard Vickers from Creepshow is really quite pleasant, even as he murders his wife and her lover.
Richard Kuklinski (Michael Shannon) in The Iceman. He's a good husband a loving father and a ruthless contract killer with a rumored tally of over 100 kills. Even creepier: the film is based on a true story.
Another one of Shannon's characters, General Zod from Man of Steel, maintains a calm and cool presence, and firmly believes himself and the other Kryptonians to be one step above human. However, unlike the theatricalZod before him, this version Zod cares about his troops, speaks to both Clark and Jor-El (including Jor-El's "ghost") as if he knew both his entire life (in the latter's case he does), and generally wants to re-create Krypton (even if that means destroying Earth to do so). He still does, however, commit violent acts like invading Metropolis and also threatening Mrs. Kent in-order to find Clark, whom he wants not only to join him but obtain his blood to reborn a new race of Kryptonians.
Dr. Hartz in The Lady Vanishes is quite a nice guy, which is shocking to modern audiences considering he turns out to be an assassin, and a Nazi at that. (The film was made in 1938, before the world was aware of the Nazis' atrocities.)
Andre Baptiste is friendly and welcoming to Yuri. Andre Junior is even worse but no less affable, if only around Yuri.
Yuri himself, who is the protagonist but is frankly an amoral (at best) arms dealer.
Uncle Charlie from Stoker is very charming, intelligent and charismatic. He's also a Creepy Uncle with a Squicky obession with his niece India and has quite the body count on his hands (Of which includes both of his brothers).
John Kramer of the Saw films is fairly approachable, polite, and truthful to the victims whom he tests and places in life-threatening, yet, escapable traps. Unlike his apprentices, John appears to genuinely want his victims to pass their tests and survive his traps. He is also honest at all times.
The villain in Notorious is about the nicest, most debonair Nazi you'll ever meet.