Editor's note: Aaron Sagers is a New York-based entertainment writer and nationally syndicated pop-culture columnist. He has specialty knowledge in "paranormal pop culture," has lectured at conventions nationwide on the topic and is a media pundit on supernatural entertainment. He covers pop culture daily at ParanormalPopCulture.com and can be found on Twitter @aaronsagers.

They are super-secret agents who sacrifice their identities and dedicate themselves to safeguarding humanity from extraterrestrial activity, all while operating undetected in the background of a society they are sworn to protect.

Starring Will Smith, Tommy Lee Jones and Josh Brolin, “Men In Black 3” is the new installment of the science-fiction film franchise in which “MIB” agents routinely save the planet from alien threats. In the latest entry, which is heavy on time travel, agents J (Smith) and K (Jones, and Brolin as the younger incarnation of the character) rely on shiny weapons to get the job done. And to keep the average citizen from freaking out about aliens, they occasionally have to erase memories using their handy gadget, the neuralyzer.

But don’t confuse the heroes of the “Men In Black” movies with the nefarious men in black suits that occupy a far larger space in the consciousness of people who believe in aliens and UFOs.

The source material for the "Men in Black" movies was Lowell Cunningham’s early '90s comic book. The comic portrays MIB as agents who track paranormal happenings and murder witnesses to contain a situation - obviously the funny good guys of the movies are a departure from the original.

The comic's treatment hews closer to other MIB theories found in popular culture (and we’re not talking about Johnny Cash or Jacob’s brother from “Lost”).

The MIB were popularized in Gray Barker’s 1956 book “They Knew Too Much About Flying Saucers.” Barker's MIB emerge in 1947 after a UFO crash in Maury Island, Washington, which coincides with the “Roswell Incident” in New Mexico. These MIB would collect data about UFOs and alien activity and threaten witnesses to keep quiet about what they saw.

Thanks to their uniform of dark suits with ties, sunglasses and hats, American folklore has proliferated the belief that MIB were federal agents. Some stories claim people encountered MIB that were also extremely pale, lacked eyebrows, and used odd speech patterns (in a very "Fringe" kind of way).

Even the descriptions of not-quite-right MIB - like the diminutive one with the cackle who may have appeared in Point Pleasant, West Virginia, around the time of the Mothman sightings in 1966-67 - convinced believers that if they weren’t feds investigating extraterrestrials, the MIB were aliens themselves.

Other theories within the UFO subculture posit that MIB are time-traveling or inter-dimensional beings popping in to observe (or warn, or control) us. The supernaturally inclined even speculate MIB could be demonic manifestations or Shadow People entities that have appeared to humans throughout history.

Whether they are identified as evil agents, aliens, demons or G-men, the MIB are a recurring archetype within entertainment, and are rarely portrayed as benevolent. As a character trope, they resonate with pop culture junkies because they are the personification of shadowy forces at work. Moreover, they represent a mysterious, yet powerful, “Them.”

Dressed in funereal fashion, with dark sunglasses that prevents eye contact - and thus human connection - they are never like “Us.” It makes sense, then, that some of the best MIBs in pop culture are either alien or inhuman. And when they are human, they are operating outside the law.

If the MIB do exist, they are hiding in the shadows. Still, they can be found everywhere in pop culture, and these are their 10 best appearances.

"The Blues Brothers" (1980)

MIB: Jake and Elwood Blues

“Joliet” Jake (John Belushi) and Elwood Blues (Dan Aykroyd) are musically inclined MIB brothers who operate far outside of Chicago law. In order to raise money and save an orphanage from closing, they assemble a team of agents to perform a rhythm-and-blues show - all the while evading pursuit by authorities, neo-Nazis, a vengeful ex-fiancee and a country music act. Their vehicle of choice, a 1974 Dodge Monaco sedan, might have a connection to alien tech and is able to perform feats such as temporary flight and flipping. While they show no evidence of inhuman abilities, they seem to be on a mission from God, are preternaturally cool with and have an uncanny ability to survive otherwise-lethal situations.

Quote: “It's 106 miles to Chicago, we got a full tank of gas, half a pack of cigarettes, it's dark ... and we're wearing sunglasses.”

"The X-Files" (1993-2002)

MIB: Syndicate, Majestic 12, Men In Black

When FBI agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) go down the rabbit hole of X-Files and begin investigating alien and other unexplained happening, they encounter a bevy of shady characters who fit the Men In Black model. As one of the prominent figures of the Syndicate shadow government - dedicated to covering up evidence of alien life and prepping Earth for an E.T. colonization - Cancer Man/Cigarette-Smoking Man (William B. Davis) is a villainous human uber-MIB.

Though he eventually goes rogue from the Syndicate, and is then re-recruited, former FBI agent Alex Krycek (Nicholas Lea) is an MIB assassin who answers primarily to Cancer Man. Krycek is human but does appear to have inhuman abilities during his final appearance on the show. The Crew-Cut Man (Lindsey Ginter) and Quiet Willy (Willy Ross) are other human MIB killers for the Syndicate. Meanwhile Syndicate MIBs Mr. X (Steven Williams) and Deep Throat (Jerry Hardin) actually proved helpful to Mulder in uncovering secrets about alien involvement, though they both seemed to have their own agendas. Following the Roswell Incident, a U.S. government agency called Majestic 12 launched to cover up UFO incidents and to adapt alien tech for human use.

Some of the members of Majestic actually refer to themselves as Men In Black, including Morris Fletcher (Michael McKean) whose job is to keep mentions of Area 51 out of the press. Fletcher claims to be the inspiration for Tommy Lee Jones’ Agent K character in Men In Black (and says he coined the term “Bermuda Triangle”).

The most likely alien MIBs on “The X-Files” are Jesse Ventura and Alex Trebek. Appearing as “Man In Black 1” and “Man In Black 2,” they wear trenchcoats and fedoras, behave oddly, and, well, look like Alex Trebek and Jesse Ventura. They appear to coerce a UFO witness, and later Mulder, that what they saw what not as it seems. Trebek and Ventura also possess a high-level of scientific knowledge and the ability to put humans into a comatose state.

Quote [from Man In Black Ventura]: “Some alien encounters are hoaxes perpetrated by your government to manipulate the public. Some of these hoaxes are intentionally revealed to manipulate the truth-seekers who become discredited if they disclose the deliberately absurd deception.”

"Pulp Fiction" (1994)

MIB: Vincent Vega, Jules Winnfield

Vincent (John Travolta) and Jules (Samuel L. Jackson) are a pair of hit men who rock the black suit like a pair of reservoir dogs (except when cleaning up brain matter with The Wolf) and do their killing with extreme prejudice. While not agents for a shadowy government organization, the two are agents for shadowy mob boss Marsellus Wallace (Ving Rhames) and his criminal network. However, it should be noted that Vincent and Jules do operate in a world of unexplained phenomena. Not only must they retrieve a briefcase containing an item of unfathomable worth, but in the process of doing so, they are miraculously shielded from harm. However, at the end of the day, the duo are badass MIBs with witty banter and a lot of personality – and personality goes a long way.

Quote: “The truth is you're the weak. And I'm the tyranny of evil men.”

"Half-Life" (1998), "Half-Life 2" (2004)

MIB: G-Man

Even though the term g-man refers to a government agent, the character in the video game series “Half-Life” does not appear to be operating in the service of a human organization. G-Man appears to observe Dr. Gordon Freeman’s endeavors to close the “resonance cascade” – and evade both hostile aliens and military personnel – at the Black Mesa Research Facility. He provides helpful information, but his aims are ambiguous and he serves unseen “employers.” In addition to the abilities of time/space manipulation, he can control certain electronic machinery and is partially telepathic. G-Man has a pale complexion that starkly contrasts his dark suits, and is noticeably gaunt with odd manicured hair and a pronounced widow’s peak. He is apparently ageless, and his speech is unnatural with fluctuating pitch. The Nihilanth aliens do allude to G-Man not being human.

Quote: “Prepare for unforeseen consequences.”

"Dark City" (1998)

MIB: Strangers

In a city of never ending night, John Murdoch’s (Rufus Sewell) day gets even bleaker when he wakes up in a bathtub at the scene of a murder with no memory. Not only is he being pursued by Inspector Bumstead (John Hurt), who thinks he’s responsible for multiple murders, but he’s also wanted by the Strangers, a group of pale, androgynous creatures in black fedoras and overcoats with psychokinetic abilities. Murdoch slowly regains his memories of his wife (Jennifer Connelly) and childhood, along with his own psychokinetic talents. He discovers his city is restructured nightly by the Strangers, and enlists the help of Dr. Schreber (Kiefer Sutherland). As Murdoch learns the nature and goals of the Strangers, he also uncovers the truth behind his own reality and the entire fabric of his city. The Strangers have a classic not-quite-human MIB appearance (eyebrows definitely not included) and are not members of a government authority; their aims are very alien.

Quote: “It seems you have discovered your unpleasant nature.”

"Matrix" (1999)

MIB: Agent Smith

It is the year 2199, and highly intelligent, sentient machines have enslaved humanity and placed them in a catatonic state, where humans are then harvested for their bioelectrical energy. Meanwhile, humanity’s consciousness exists within a virtual reality version of 1999. Eventually a group of human resistance fighters become aware of the Machine reality, and begin to manipulate the physics of the virtual world, as well as learn to unplug and enter the “real world.” The Machines dispatch Agents - essentially superpowered, nearly omniscient computer program "antibodies" that look like MIB with very stern expressions - to deal with the threat posed by resistance leader Morpheus (Laurence Fishburne) and hotshot recruit Neo (Keanu Reeves). Agent Smith (Hugo Weaving) is the most advanced of his kind, and can slip in and out of space and slow down time. A lethal, intimidating force that cannot be evaded, Agents are more powerful than (most) humans.

Quote: “Human beings are a disease, a cancer of this planet. You're a plague and we are the cure.”

"Fringe" (2008-2012)

MIB: The Observers

Having appeared in every episode of Fringe, The Observers are beings who seem to possess telepathic abilities and can apparently travel through time and space. They are pale, bald and lack eyebrows; they wear black suits, with a fedora and sometimes sunglasses. The Observer named September (Michael Cerveris) has a dulled sense of taste with a high tolerance to spicy foods, speaks with awkward phrasing and writes in an alien language. He seems primarily concerned with Pattern events and the Fringe division. While they have knowledge of human history and future - and have been spotted at significant historical events - they are not omnipotent. Most of the time they simply watch the activities of man, but have at least once attempted to eliminate a person from existence. Although they operate within a hierarchy and report to a superior, they maintain individual personalities and can choose to rebel. If they are not alien, there is a possibility that they are a highly-evolved human from the future.

Quote: “I have said too much, I am not supposed to get involved. I have taken you as far as I can”

"Iron Man" (2008), "Iron Man 2" (2010), "Thor" (2011), "The Avengers" (2012)

MIB: Phil Coulson

As an operative for the Strategic Homeland Intervention, Enforcement and Logistics Division (that’s SHIELD, in case you didn’t know), Coulson (Clark Gregg) looks about as straight-laced as they come. An agency man, Coulson is a nerdy fanboy who idolizes Captain America and has been called the glue of the Marvel Comics movie universe by recruiting Iron Man and Thor into the Avengers Initiative (as well as doing a few other spoilery things in the new Avengers flick). Although he is an unassuming character who can blend into the background, like a great MIB - compared to his eyepatch-and-black trenchcoat-wearing boss - Coulson is a red-blooded human. But he is also tough enough to take on a demigod and wrangle a billionaire playboy.

Quote: “This isn't my first rodeo, Mr. Stark”

"The Adjustment Bureau" (2011)

MIB: The Bureau

The life of David Norris (Matt Damon) was going according to plan – until he boarded a bus he was supposed to miss. After coincidentally reuniting with a woman from his past (Emily Blunt), Norris gets to his office early and walks in on men-in-suits from The Bureau “adjusting” a frozen reality. Bureau men Richardson (John Slattery) and Thompson (Terence Stamp) reveal humanity has botched its gift of free will and is now kept on a plan laid out by the Chairman - which includes preventing Norris from being with the woman he loves. More than the Philip K. Dick short story “Adjustment Team,” the movie plays up the MIB element of agents and puppeteers. The Bureau-men appear human and seem to require sleep, but also possess extra-human abilities, use advanced technology and have knowledge beyond normal man. Instead of alien, they seem to belong to a “higher” power.

Quote: “We are the people who make sure things happen according to plan.”

"Doctor Who" (2011)

MIB: The Silence

Combine the Men In Black with alien Grey, with a dash of Edvard Munch’s “The Scream” and the stuff of the worst bogeyman nightmares and the result is The Silence. A religious species of aliens, Silence are tall, shriveled-up beings without mouths who wear black suits constructed of seemingly organic material. Their powers include the ability to emit an electrical energy to destroy a person. But their real power is the ability to post-hypnotically implant suggestions in the mind, and force a person to immediately forget an encounter with them. They are super parasites who have effectively controlled Earth for millennia.

Quote: “This world is ours. We have ruled it since the wheel and the fire. We have no need of weapons.”