Before we get to the List itself, there are three characters who I can't not mention who I nonetheless felt as though did not fit the parameters of this list.
Disqualified on Basis of Not Being "of the Week"
3.) The Well Manicured Man- Often occupying the role as the "reasonable" face of the Syndicate, the real delight of Manicured is the way he would show up and unsubtly but also unemotionally remind Scully and/or Mully that the Syndicate could kill without it raising their collective heart rate even a bit. A nice counterbalance to the Cigarette Smoking Man's (see below) rough and dirty approach to their problems, Manicured almost always used soft power to achieve his goals.
2.) Krycek- The mole within, Mulder's mirror in the employ of the Syndicate, the one-handed rogue only out for himself--Krycek was all that. As dedicated as Mulder was to actively unearthing the truth, Krycek was dedicated to suppressing it. As Mulder was moral and trying to achieve that which he believed would be best for all, Krycek's only motivation was whether or not he would benefit from doing this or doing that. Nicolas Lea nicely "lived" each of Kyrcek's evolutions, making them wholly believable and different enough to convey just how empty, and thus able to take on nearly any personality, he was.
1.) The Cigarette Smoking Man/Cancer Man- While he also had bosses to answer to, CSM was mostly the string pulling antagonist who always seemed to snatch Mulder's victory away from him in the last moments. It is a credit to his character that even as the show filled in his backstory and, arguably, humanized him, he remained an avatar of evil without measure. It has only become more clear as the years pass and smoking becomes even more restricted, but CSM is the avatar of the old order fighting like hell to keep things same as they ever were so he and his masters can continue to gain and wield power.
Ok, with those guys out the of way, it is now time for...
X-Files Human Monsters of the Week, in Order of Personal Preference (and by no means fully comprehensive)
25.) John Barnett- A bank robber and unscrupulous murderer, Barnett was reversed aged by Doctors who experimented on his in prison. Young again, Barnett sprung himself from prison and proceeded to target Mulder's still living loved ones. Barnett was both a monster (in the "of the week" sense and the common vernacular version) and a victim, an early example of how X-Files could construct a truly scary villain while still showing him or her to be a bit of a puppet of larger circumstances.
24.) Erwin Timothy Lukesh- Lukesh as a character is a bit "eh" truth be told, but his ability to travel between alternate versions of our universe allowed the episode he appeared in to be a real mind bending corker.
23.) Ken Naciamento- A fictional character "born" into the real world, following through on the crimes he was written committing in the novels he came from, Naciamento was it of X-Files traversing Stephen King territory. Even if vast swaths of it felt like Dark Half or Secret Window though, the episode and character deserve praise for the moment in which Naciamento and the writer that created him meet and lock horns over the nature of fatalism.
22.) Edmund, George, and Sherman Peacock- Confession: I hate "Home" the episode these deformed brother hail from. Proclaimed as one of X-Files' masterpieces, I have always found it overly dark (in lighting) and ugly (in nearly every way). It certainly pushed what you could get away with on network TV, but...so?
Nonetheless, the brothers are legitimately horrifying and thus unforgettable.
21.) Detective B.J. Morrow- Evil as a family legacy (actually anything as a family legacy) is something that X-Files repeatedly returns to over time and this was one of the earliest examples. Morrow was a good cop in a small town, but also the illegitimate child of a sociopathic murderer. And sometimes, well, as they say, these things are in the blood.
Utterly unconvincing as an explanation, Morrow nonetheless rings ever tragic drop out of being a killer by birth trying to do right, not wrong.
20.) Anthony Tipet- A very late in the run human monster of the week, Tipet injected some much needed life into a show that appeared to be on its last legs. With his third eye and bizarre mashing of Eastern and Western religious practices, he made for a striking visual who was equal parts scary and interesting.
19.) Marty Glen- She is blind yet she keeps showing up at crime scenes with details only the killer should know. And why is there so much evidence that seems to indicate her guilt?
Lili Taylor is great as Glen and, honestly, I wish I could put her lower on the list. Unfortunately, the episode's weird insistence on blind people as so disabled as to be incapable of most things and the ending, which strives for profundity but lands in "that would never happen, suspended disbelief or not" always colors my memory of the character.
18.) Edward Funsch- It is hard to call Funsch a monster in many ways, but then there he was opening fire on random people with a high powered rifle. One again though, Funsch is a monster who is actually a victim of factors far larger than himself. The truly sad thing is that Funsch, unlike other "MotW's", really would be an average guy if not for the one moment where it all went awry.
17.) Gerry Schnauz- Schnauz was utterly convinced that what he was doing heroic work, "saving" his victims from "howlers" by performing ice-pick lobotomies on them and all the scarier for it. He also had a couple of great gimmicks, wearing stilts to make himself taller (and thus less likely to match a police description if someone might witness his activates) and taking pictures that depicted the women in them as being terrified and attack by the "howlers."
16.) Agent Bill Patterson- Another one in a series of mentors turned monsters, Patterson was obsessed with a case and, perhaps, became the murderer he hunted. Part of a moody, atmospheric episode long on images and short on plot, Patterson nonetheless warrants mention as the episode's scariest example of its thesis that violence is a virus that alters everyone it touches. Also, intriguingly, as Patterson is dragged away, proclaiming his innocence, it is not entirely clear he is not telling the truth.
15.) The Eves- "Twins are creepy" is a truism on par with "Clowns are creepy" and the Eves tap into that. They are antisocial (in the psychological sense of the world) second or third generation clones who have worked together to pull off a convincingly oogy murder, framed earlier generation clones for it, killed at least one of those earlier gen versions of themselves and nearly killed Mulder and Scully via poison. Also in their favor is that, in the end, they are sent to Whiting which, of course, has to be Whiting Forensic in the great state of Connecticut.
14.) Robert Gailen Orison- A prison chaplin and former murderer himself, Orison had, via an accident in the mid-50's gained both the ability to use group hypnosis and the belief that he was chosen by God to kill criminals. To that end, he would hypnotize prison guards to ensure certain prisoners escape and then hunt them down. I love the twist of the "good" man who's declared himself executioner, an irony added to by Orison's past crimes and current occupational choice.
13.) Patrick Crump- Unpleasant, dangerous, and anti-Semitic, Crump is nonetheless an innocent victim more than a monster of the week. Still, he took Mulder hostage and that is enough to get him included here. Brian Cranston is called upon to engage in screaming, wilting, cringing, and ranting while still creating a character you can care about, and he nails it.
12.) The Fortune Teller Killer- Although Peter Boyle's depiction of death psychic Clyde Bruckman is the centerpiece of the episode (and for good reason), Peter Charno's Killer is a weird delight. Driven to find out why he does what he does, Killer keeps seeking fortune teller types and killing them immediately afterwards.
The way he plays the moment he's told be by Bruckman that the reason he kills is because he is a homicidal madman would get him on the list alone. It is a perfect bit of underplay; one really believes that that news makes him feel better.
11.) Simon Gates- A religious zealot driven to seek out stigmatics and kill them. With a shock of white hair and the veneer of respectability money buys, Gates moved through the world largely unsuspected. The true fascination of him is that he is not killing to punish the fakes, but rather he is killing to hopefully kill a "real" stigmatic and thus bring back a new era in life on Earth.
10.) Margi Kleinjan and Terri Roberts- Best friends who share a birthday, they apparently gain tremendous powers because of the alignment of the planets. However, Margi and Terri's choice to immediately use their powers to maim and kill marks them as monstrous independent of the psychokinetic boost. Unlike, say, Darin Oswald who reacted out of impulse with his powers, these girls were killers inside just waited for an opportunity.
9.) Chester Banton- A true tragic beast, Banton's shadow gained dangerous powers through an experimental accident. Largely beyond his control, he accidentally killed several before Mulder and Scully could bring him in. He makes the list based on Tony Shalhoub's soulful depiction of him. The way Shalhoub lets Banton's desperation and paranoia mount until it boils over, turning this average man into a vengeful killer who really, truly only wants to die.
8.) Warren James Dupre- Another Season 1 monster who's "first" career in villainy was bank robbery....an odd thing considering the number of bank robberies in the U.S. a year versus the number of monsters in season one. In any case, Dupre was seemingly slain during a failed attempt, but actually ended up in the body of Scully's mentor. A PTSD metaphor that falls apart as the episode runs down, it is nonetheless, in the early going, an affecting depiction of how being exposed to tragedy can seem to alter your very DNA.
7.) Augustus Cole- An experiment in creating the perfect soldier gone awry, Cole was part of a battalion of soldiers who had been altered in such a way as to no longer need sleep. Apparently driven a bit mad but this change, the team committed huge atrocities in Vietnam. Years later, Cole, somehow empowered by his sleeplessness to create hallucinations, and sought to punish his fellow soldiers who their war crimes. However, he was equally guilty and therefore saves the proverbial last bullet for himself, a monster who knew he was too dangerous to exist in the world any longer.
6.) Donald Pfaster- There is some argument to be made to have Pfaster on the Humanoid (but Non Human) Monster list, but I tend to subscribe to the theory that the "shape shifting" he exhibits are hallucinatory reactions to the extreme horror the victims are living through and that Pfaster is no literal demon.
Plus, Pfaster is infinitely more frightening as a human being kills and fetishizes death. A demon's nature is to be evil, a person is making a choice to do these horrible things.
5.) Darin Peter Oswald- A volatile teen with lightning powers seems like a recipe for disaster and X-Files delivers exactly that with Oswald. A still developing impulse control and moral center means he reacts first, more often violently, and only pauses to consider what he's done later. Scary and funny in equal measure, Oswald was a twitchy hypnotic delight.
4.) John Lee Roche- Tom Noonan cannot help but give off a kind of cracked scary, be it as Frankenstein in THE MONSTER SQUAD or as the Tooth Fairy in MANHUNTER and he brings that to bear hear as well. Another monster who made it personal by claiming to be the one responsible for the kidnapping and eventual murder of Mulder's sister, Roche had a calm understated quality to his menace that made his perfect to be realized by Noonan.
3.) Luther Lee Boggs- An imprisoned serial killer claiming to be psychic, Boggs came across as Hannibal Lecter filtered through FEAR's Shadow Man. One of the earliest versions of someone playing upon Scully's faith and vulnerabilities, it remains arguably the strongest of the bunch. A lot of this is owed to the story structure that never tips its hand to reveal whether Boggs is psychic or just an accomplice of the murderer who he is "seeing."
2.) Duane Barry- Although barely able to function in the world, no human monster, arguably, proved as dangerous to Mulder and, especially, Scully than Duane Barry. Barry, claiming to be a multiple abductee, is a showcase of sweaty, stuttering, wild acting. Caught between wanting to help Mulder and Scully because finally there is someone who believes him and saving his own skin by selling them out, Barry is a covert danger. So damaged, no one takes him seriously, but just damaged enough to do the truly inhuman.
1.) Robert Patrick Modell/Pusher- The "monster" of my single favorite episode of the X-Files ever, everything about the character worked for me. His power, the ability make people do, say, or see what he wants including, even, "convincing" a man's heart to stop beating via phone call, was one of my favorites; so simple but with such devastating power. Modell was also written to be painfully mediocre and uncool. His wardrobe is brutal, and because it reflects the fashions of the time, his apartment is bland, his intimate relationships non-existent. He was an utterly banal villain who just happened to have been gifted a terrifying power.
I also have to throw out the Russian Roulette scene between he, Mulder, and Scully as an absolutely perfect piece of pressure cooker intensity done on the small screen.
Modell did show up again, about two seasons later, in an episode that is a fascinating watch if, for no other reason than it lets you watch the same team that got it so right the first time around completely misuse their character the second. Modell is almost totally passive in the episode and only a scene where Mulder is led to believe he just watched Scully kill herself holds any punch--and that wasn't even Modell's act.
Nonetheless, he remains my favorite monster, an utterly unremarkable guy who turns out to be one of the most dangerous people on the planet.