Glamour

Traditionally, The Fair Folk are reputed to have a powerful and subtle magic that disguises their true (and less than fair) form into one that is beautiful, beguiling and beatific. This was called a Glamour. It not only cast an illusion of physical perfection, but made any hapless viewer think of the fae as graceful, wise, a lifelong friend, and made them easily suggestible if not utterly enthralling them in More Than Mind Control.

Now imagine a character who has this power, and can use it on crowds. We'll wait for you to stop shivering.

Characters with this power become the center of attention. Anyone who looks at the character will suffer effects similar to Love Is in the Air: they'll consider the character to be flawlessly beautiful, smart, funny, and fall over themselves to do whatever the character says. While this isn't direct Mind Control or a Charm Person, it does affect people psychically by making them want to help the character. Sort of a cross between Mass Hypnosis and The Charmer. While weak glamours or strong willed characters probably won't do unethical things or that go against their interests, they will act at least slightly out of character while under its effects: disliking the character will seem unnatural, arguing against them impossible, and attacking the character would be like committing blasphemy. When it's a powerful glamour (or a Weak-Willed victim) victims won't hesitate to obey any of the character's whims.

But as soon as he or she leaves the room (or a certain ammount of time passes) the former awestruck followers will get the psychic equivalent of a hangover and wonder what the heck happened. If the character has an especially powerful Glamour the effects may be permanent, require either special shielding to cut off, or the equivalent of Mind Control deprogramming to return victims to normal. If a character has God Mode Sue class Glamour, nothing less than killing him or her will end the spell.

This is usually a borderline case of Bad Powers, Bad People. An ethical character that doesn't abuse those affected might actually accrue less Mind Over Manners related Squick than using straight Mind Control. As a power, it does have a certain degree of Blessed with Suck. If the glamour can't be turned off the character may very quickly despair at having no intelligent conversation since everyone agrees with them, no real love since anyone they meet will instantly love them, and otherwise having all the conflict leached out of their life.

Since this is basically a character trait of Mary Sue Classic turned into a power, it is often explicitly wielded by Parody Sues in fanfiction. When this power fails or comes into conflict with an equal and or greater Glamour, sparks fly.

Often the explanation behind a Weirdness Censor or Invisible to Normals.

The term, incidentally, derives from "grammar". Like what you learn in school. But since "grammar" was the first of the liberal arts, it came to mean "book learning", and Rule of Cool demanded that it be used for the coolest form of book learning: magic.

Compare Artifact of Attraction and Getting Smilies Painted on Your Soul. If dispelled, causes a Glamour Failure.

Not to be confused with the American Fashion Magazine.

Anime and Manga

 * Code Geass: This was, due to the powers provided by the geass being according to the user's biggest desire, and her biggest desire was to be loved (she was a slave). After a while she lost the control of her powers and the only person she cared about, was the nun that gave her the geass, because she was the only person immune to her power.

Comic Books

 * Poison Ivy has this power in Batman comics, but it's probably at its most noticeable in Batman and Robin, where every man she stands near becomes instantly attracted to her. Apparently it's due to "plant pheromones" or something.
 * The Runner from Marvel Comics has an undefined ability to make people enjoy his company. It doesn't prevent people from attacking him, which results in the occasional amusing fight scene.
 * Black Orchid can do this in the ongoing series that followed Neil Gaiman's miniseries.
 * This is Allure's power in Relative Heroes in The DCU.
 * Gambit (Remy Lebeau) of the X-Men has a hypnotic charm, an ability to "charge" the kinetic energy within a person's brain, allowing a subtle influence over any sentient mind. This power allows Gambit to compel others to believe what he says and agree with anything he suggests.

Literature

 * Perfume, a novel about a troll-like man with a heightened sense of smell who is on a quest to create a perfume so beautiful that it will make all who smell it believe they are in heaven.
 * Another classic trope example would be the elves of Discworld, who have this as their deadliest weapon.
 * Elves are wonderful. They provoke wonder. Elves are marvellous. They cause marvels. Elves are fantastic. They create fantasies. Elves are glamorous. They project glamour. Elves are enchanting. They weave enchantment. Elves are terrific. They beget terror. The thing about words is that meanings can twist just like a snake, and if you want to find snakes look for them behind words that have changed their meaning. No one ever said elves are nice. Elves are bad.
 * Also from the Discworld, the charismatic Captain Carrot might have this, but balance of the evidence is that he really is just that good.
 * In The Dark Tower series (and a lot of other books by Stephen King), there exists a (kinda )subtle type of magic, and along with it a type of Glamour. Used quite often to veil Eldritch Abominations from, well, everyone that doesn't want to Go Mad from the Revelation. Which is quite a bit of people.
 * In Sword of Truth books, Witch Women like Shota or Six do this unconsciously, and sometimes unintentionally, to those around them.
 * In Shannara books, (namely the Sword of Shannara), a siren uses a glamour to appear as a beautiful woman sitting by a tree just before the tree eats a hapless traveller.
 * Star Trek: New Frontier: The Selelvian race has a form of Glamour that's called "The Knack". They claim it only makes a person do what they really want to do, but it is eventually shown that they can make others do what they want them to do. It doesn't work on nonbiological beings, so Morgan (a hologram) and Data (an android) are able to bust them, leading to an off-pages war.
 * One of the original "Four Aces" in the Wild Cards series, Envoy, does this through pheromone control. HUAC finally makes him testify in a sealed booth.
 * Skulduggery Pleasant: Everyone who sees China Sorrows for the first time falls in love with her. As Skulduggery notes, the effect lessens significantly once you get to know her.
 * The Dresden Files makes a few mentions of fae folk casting a glamour, and says that all those 'glamorous' actresses in the world wished they could look like the fae.
 * In addition to The Fair Folk, there are the vampires of the White Court. Lara Raith has such a powerful glamour that when she turns it up, just being anywhere nearby could be mind-breaking.
 * All paranormals in Paranormalcy have some sort of glamour to hide their true features: vampire glamours look normal to hide their shrivelled corpses; werewolves use them to hide their Eyes of Gold and wolf form on the full moon; and faeries use them to tone down their unbelievable good looks.
 * The Laundry Series has a glamour as a spell any mildly-skilled sorcerer can cast. They're ranked on a scale of one to five, with one being "cover up minor imperfections," three being "make a humanoid entity look perfectly human," and five being "instill outright worship." At one point, Bob buys an iPhone and silently curses to himself that someone at Apple must be casting class five glamours over them.
 * In Tom Holt's J.W. Wells books, there is an entire department in J.W. Wells and Co. devoted to glamour. It is run by the The Fey and their biggest, highest-paying clients are celebrities and politicians who are looking for more publicity. The Fey and their part-human descendants are particularly good at "effective magic" which affects the viewer's mind and perceptions, while other types of magical beings prefer "practical magic", which changes the physical structure of things.
 * Sheri Tepper's True Game series has certain characters who possess the talent of Beguilement, which makes the wielder seem more attractive and charismatic when it is used. Powerful Beguilers can make themselves seem irresistibly attractive even if their true bodies are deformed or disfigured.
 * In Camille De Angelis's Petty Magic, beldames can cast a variety of glamour spells that let them disguise their true age, take on someone else's face, etc. The older, more experienced ones have learned that while it can sometimes be fun to look younger and more attractive, the most useful glamours achieve the reverse effect-making one seem bland, boring to look at, and completely inconspicuous, which is particularly useful for anyone doing government work or espionage.
 * Used the traditional way in Jonathan Strange & Mr Norrell: As soon as the gentleman with the thistle-down hair, who used to look like a beautiful human male, is in death's clutches, he starts losing his Glamour and reverting back to his weird, ugly, animal-like true form.
 * The Shapeshifter series has illusions, persuasions and invisibility as types of glamour. A character not being vulnerable to two of these is a major plot point.

Live Action TV

 * In The 4400, Graham Holt took the Promicin shot and gained the ability to make anyone who walked within a certain distance of him to worship him and do anything he told them to. Eventually he had most of the city brainwashed, along with members of the Army and the police force. He could make them do anything, including violate the law. Also, his control didn't go away when the affected person left his vicinity. He was only stopped because  took away his ability. (Why he didn't fall under Graham's power himself was never explained.)
 * Jasmine on Angel used a high intensity permanent Glamour that was visually transmitted to try and Take Over the World.
 * Simon the Likable from the Get Smart episode "And Baby Makes Four". A vicious agent, when you look at him, you can't help liking him. This like is so powerful that no one can arrest, or even stop, him.
 * On Stargate Atlantis, a man called Lucius Lavin is able to take over Atlantis through the use of a Glamour potion. Unfortunately for Lucius, the potion doesn't work on people who can't breathe through their noses, so Colonel Sheppard and his head cold end up saving the city. Then, McKay gets hold of the potion just in time for Sheppard (the only person not given the potion antidote) to get over his cold.

Meta

 * Our Vampires Are Different, but some kind of glamour-type magic (or just full on hypnosis) is generally part of a vampire's arsenal.

Tabletop RPG

 * In the Scion roleplaying-system, powers like these can be wielded by scions with high stats in Appearance (positive) and Charisma. Basically, they're either so unearthly beautiful that you cannot help but be smitten with them at first sight, or so incredibly charming that you'll be hanging on their every word. Having either of those stats maxed out (or, GM forbid, BOTH) puts you on a level where you can have this sort of effect on the very gods!
 * A lot of splats in the The World of Darkness have some variation of this, ranging from "life of the party" to "so glorious even considering disagreement requires you to exert great willpower, let alone harming them". They included both of the Vampire gamelines, Demon, Werewolf: The Apocalypse, Changeling: The Lost, and obviously Mage: The Ascension and Mage: The Awakening through Mind effects.
 * Exalted, oh Christ, Exalted. Let's just start with the fact that the Raksha outright call the abilities they use to appear as beautiful ravishers and demon-whores "Glamours." Then there are the various social powers of the Exalted, which range from "everyone in this social group finds this suddenly taboo" to "everyone who watches me dance falls utterly in love with me, regardless of sexual orientation" to "you find my words stir up shame and loathing within yourself." ... With special mention to "you rationalize my every action as being virtuous".
 * Much like Scion which followed it, Novas in Aberrant with Mega-Charisma, Mega-Appearance (beauty), and/or Mega-Manipulation can provoke love at first sight or have a hypnotic voice, in addition to the bonuses they get on ordinary social tasks that anyone can attempt.
 * In 7th Sea, the sorcery associated with Avalon IS called Glamour, with a few of its knacks able to make the sorcerer more beautiful for bonuses to social skill checks. Likewise, Scryers of Sophia's Daughters get for free the Above Average Appearance advantage (or reduce the cost for Stunning or Blessed Appearance advantages) as part of their sorcerous package. Also, the advantage "Dangerous Beauty" is specifically used for seduction attempts.

Video Games

 * Naminé in Kingdom Hearts: Chain of Memories can rewrite people's memories so that they think she's their childhood friend and they're in love with her and so on, if that counts. It's not a sudden "as soon as she walks into a room everyone there is in love with her" kind of thing, but it does make her function in the story much the way a Mary Sue would in a fic, except that you're supposed to be thinking "wait who is this chick and why does Sora care so much about her all of a sudden". Part of the reason that she is not a Mary Sue is that her power has a very narrow range of people that can be affected by it: she can only use it on Sora or those who are close to his heart.
 * Male Morrigi from Sword of the Stars have a sort of psychic glamour, allowing them to project an impossibly beautiful image of whatever species they're currently engaged with. Those images all possess wings, so a human might see a beautiful angel, for example.
 * As All There in the Manual reveals, Female Morrigi have an opposite functioning Glamour that makes them look more fearsome and dangerous than they really are.
 * Arguably the Jedi Exile has this ability, pulling people in and getting them to do what they otherwise would not. It's much more pronounced if you use this power for evil, as your party members snap out of it after killing whoever you've set them against and react with horror.
 * Presumably this is how the move Attract works in Pokémon. If it hits an opponent of the opposite gender, they end up infatuated and may not be able to make a move. The effect wears off after the battle ends or the affected Pokémon is switched out.

Web Original

 * "The Thnikkaman" (AKA Bubs with sunglasses) in a few Strong Bad E-Mails. His very appearence, whilst doing nothing impressive, can pretty much lead to both character and plot derailment due to characters fawning over him. Did we mention that his catch phrase, which no one seems to mind, is "yeah, shut up kid"?
 * In the Global Guardians PBEM Universe, The Charmer's whole power is getting people to like her to the point that they'll do anything she wants. Ambrosia uses super-pheremones to do the same thing, but only to men.
 * Fey, Imperious, and Carmilla have this. Imperious has abused it, at one point going to the level of Mind Rape. They are all beings who one would expect to have such a power. Fey is a queen of The Fair Folk. Carmilla is a Cosmic Horror who is a Horny Devil. Imperious is an incarnation or avatar (or something) of Zeus himself.

Real Life

 * This is how certain individuals who claim to be part-dragon justify the fact that no one else can see their supposed claws and scales. Insanity, perhaps, but a shared insanity if so—they even have Internet support groups! (They're generally classified as a particularly out-there branch of the Otherkin, themselves an out-there branch of the Furry Fandom.)
 * Hey, here's your dose of Paranoia Fuel today. Modern neurology, while advanced, isn't quite exact. Technically it wouldn't be defying modern neurological science for this to happen. Not paranoia fuel yet? well there's also a distinct lack of proof that this hasn't been done subconsciously by everyone you love.
 * Oxytocin? If one could secrete it into the air...