Slan, an Apostle, and one of the members of the God Hand. As if her creepy lack-of-outfit wasn't clue enough, during the Eclipse when Casca is being raped by Griffith Slan watches on and cries tears of joy.
A later less-sadistic, but still quite disturbing, example would be Sonia, a little girl and member of Griffith's new Band of the Hawk who is, unlike the rest of the world's populace, unafraid of the Eldritich Abominations known as Apostles.
Cardcaptor Sakura had the Meganekko Naoko Yanagisawa who, during a conversation about a haunted house, mentioned that she "like[d] that sort of thing." The manga included visual aid of "that sort of thing" (UFOs, ghosts, monsters, unusual temples and shrines). Of course, this tends to creep the living hell out of poor Sakura.
Magical Pokémon Journey's Hazel likes cute Pokémon, but her definition of "cute" extends to species that aren't generally considered such, including Gengar and Tangela. She's so friendly toward Pokémon that she'll help them with whatever their problems are, no matter what said Pokémon look like, even to the point of facilitating an Interspecies Romance between a Wigglytuff and an Arbok, which is entirely possible in-game.
The series has a lot of characters who are involved in Dirty Business and are willing to play jump rope with the Moral Event Horizon. Then you get Omnicidal Maniac Ladd who literally dances in blood and considers "I'm gonna kill you last" as an endearing term to use with his girlfriend. She is completely accepting of this.
On the darker side of this trope you have the immortal Fermet and Huey who only see other people as human components For Science!. This leads to them doing some rather despicable things as a means of enjoyment. Fermet in particular had a grand old ball torturing and killing immortal child CzeslawMeyer repeatedly for upwards of 200 years.
Ranma ˝'s Gosunkugi apparently harbors a fetish for voodoo dolls in the manga. In the anime, it's amped up to more of an obsession with magic in general- particularly the creepier side of things. In one episode, he falls in love with Cute Ghost Girl Kogane, not being even the slightest fazed when he discovers her undead nature. His ideas of dates also include showing off his collection of occult lore (which happens to fixate on curses) and a romantic rendezvous in a purportedly haunted graveyard.
Rena spends her afternoons in the local scrap yard collecting whatever she finds cute, including her trademark cleaver and a statue of Colonel Sanders.
Droopy nurse Takano Miyo, who is a Fangirl for the dark legends about Hinamizawa's dark past.
Rei Takashima from Deadman Wonderland, a twisted doctor who is not merely a sadist, but actually aroused by human suffering and mutilation.
From The Wallflower / Yamato Nadeshiko Shichi Henge: female lead Sunako Nakahara is a lover of solitude, gore movies, banned gore movies, anatomical dolls and objects that reflect "the ugly side of life," as she puts it. Not to mention that she tends to be pretty creepy herself.
Nico Robin finds three-headed zombie dogs "cute." When introducing herself to the Straw Hats after the Alabasta arc, she smiles while mentioning her specialization is assassination. Throughout the whole series, Nico Robin is able to talk about disturbing topics like death, dying, blood, etc., as casually and cheerfully as most people talk about the weather.
From the same arc as the three-headed zombie dog is Elegant Gothic Lolita "Ghost Princess" Perona, who describes her ideal vacation as going to a "dark, dank, haunted, ancient castle, singing songs of curses and having a miserable old time." Kuma then sends her to one of these; she realizes that it really is miserable without servants tending to her every need.
In Yes! Pretty Cure 5, Komachi is the only one not particularly frightened by the haunted house they encounter in one episode, not even when they discover a painting of someone who looks exactly like Rin. In fact, she thinks it's exciting. This is part of an ongoing tendency of hers to get excited about things (like becoming a Runaway Bride) that nobody else would see as positive.
Minori from Tora Dora, who goes so far as to trick people into scaring her.
And gets a nosebleed (complete with spurting blood) from the possibility of her class setting up a haunted house for the school festival.
When Taeko of Ai Yori Aoshi was given the breaking-in task of the photography club (going out into the woods and photographing a ghost), she leaped at the chance, much to everyone else's confusion. What's worse, she apparently succeeds. Later on, in a haunted house, she is seen laughing at all the things and calling them cute. For effect, the other two girls are completely freaked out and clinging, in tears, to poor Kaoru.
Ouran High School Host Club has Nekozawa and his friends from the Black Magic Club, who are obsessed with curses and all kinds of creepy things. They're quite a happy bunch, too.
In Chrono Crusade, upon discovering that Chrono is a bona fide demon, Joshua doesn't freak out so much as he jumps for joy and eagerly asks him if ghosts exist, too.
Drosselmeyer delights in tragic stories and gets excited whenever things begin to take a dark turn.
Autor, being a Drosselmeyer fanboy, is implied to be like this as well—he finds the powerful ability to manipulate people by writing stories to be "thrilling".
And then, in season 2, there's Mytho after his heart is tainted with Raven's blood. When another character is about to cut out his heart, he requests they "kiss it and dye your lips red with its blood".
MariIllustriousMakanami from Rebuild of Evangelion really, really likes the smell of LCL - a really sticky, orangeish-red liquid which, according to the protagonist (who was seriously creeped out by that stuff on a few occasions), smells like blood. It gets even more disturbing if you know that it actually IS blood - from the angel Lilith who is a giant, featureless white monster with tons of little, moving human legs sticking out of where the lower body should be. Squick.
In Get Backers, there's Takuma Fudou... who seems to get turned on by some pretty messed up things. Like the idea of "slurping up" Ban's blood, as well as him "feeling incredible chills rising throughout his body" when he kept his maggot-infested arm with him to remind himself of Ban.
Furuya from the manga Sankarea is pretty much all about this trope. His nightmare fetish for zombies is what catapults the entire plot, since he decided (for his own ego's sake) to try to resurrect his pet cat Babu into a zombie. Just to see if he could.
Hidan, one of the Akatsuki members from Naruto, enjoys pain, be it his own or his enemy's.
Leo once tried to touch some people who have suffered Body Horror more out of wonder than anything. An omake also shows him declaring interest in the mangaka's Author Avatar's insides with a smile on his face.
Shinra of Durarara makes it known that he thinks Celty is beautiful without a head. He also spent most of grade school and high school fanboying Shizuo's crazy rage fits.
Emotionless Girl Anju of Karin habitually carries around Boogie-Kun, a doll possessed by a serial killer with a knife in its hand. Angu tells Karin Boogie-Kun's past history with a cheerful smile on her face and later mentions that she collects other creepy dolls that all have interesting histories.
Ryuuko of Wolf Guy - Wolfen Crest gets turned on by violence to the point where she masturbates on top of a school rooftop after a few students had been gunned down there.
Karate Shoukoushi Kohinata Minoru: During their fight Kevin gets excited at seeing Minoru's fearful eyes, grabs him by the throat and squeezes hard enough so as to make him cough up blood. He then drinks the blood while saying "Mmm...Delicious flavor...LET ME DRINK MORE!"
Maylene goes into fangirl mode upon seeing a mummy in episode 4.
Grell gets really excited at the thought of both cutting Sebastian into pieces and having his babies.
Undertaker enjoys the feeling of having the water sucked out of his body while being buried neck-deep in salt.
Aki Hinata from Keroro Gunsou finds slimy, squishy things adorable and squees at the thought of Keroro's race secretly being hideous pudding monsters or something. This is explained by her being the editor of a manga for boys. Yet there's a lot of scenes of her being molested by weird, slimy monsters for some reason... and enjoying it.
Boku and Morino from Goth are a pair of nightmare fetishists who investigate murders in hopes of uncovering the evil that lurks within their society. Boku doesn't flinch when the remains of a murder victim is found, as he wants nothing more than to see someone die in such a fashion even if that person is Morino. Morino even went to the extent of wearing the clothes they found near a mutilated and decayed body, just to see what it feels like.
Conan (aka Shinichi), Heiji, and occasionally the Shounen Tantei often see bloody and violent crime scenes as exciting or interesting challenges.
Right at the beginning of the series, when Ran is crying after seeing a man get messily decapitated on a roller coaster ride (with the resultant fountain of blood), Shinichi is cheerful and assures her that "this kind of thing happens all the time".
Mariko Shinobu from Oniisama e... seems to be this. She tells Nanako and Tomoko the story of two Star-Crossed Lovers who got into a Suicide Pact almost with glee, apparently thinking it's the most romantic love story ever.
Ragdoll of the Secret Six. He happily accepts the description "the bent little castrated horndog" and delights in his ability to make absolutely any word or phrase sound unsavory, from "to my batpole!" to "cheese-stuffed manicotti".
And then there's Black Alice, the first person in-universe to find Ragdoll hot. Even Ragdoll was squicked out by this.
Especially in the 2011 "New 52" release of Detective Comics (Issue #1).
The Scarecrow, operating as he does off of creating fear, embraces this role wholeheartedly.
Willie Pete of Empowered lives this trope. His name may be another name for White Phosphorus, the other implication from the name is in full effect, and often introduced to the skulls of his victims, particularly the eyesocket. Using his own willy, no less.
Kid Gladiator, the son of X-Men foe/ally Gladiator. His reaction being turned into a Brood? He thought it was awesome, and protested being transformed back to normal.
Fluttershy has a moment of this in issue three of My Little Pony: Friendship Is Magic (IDW) when a chupacabra and a pack of vampiric jackalopes battle (presumably to the death) for the right to eat the Mane Six, and Fluttershy watches with captive awe at the "fascinating" creatures.
Saga and Luna in Under The Northern Lights. It seems to be the proscribed aesthetics in the Temple of Hrimfaxi, which looks like a "haunted stable on Nightmare Night" according to Twilight Sparkle.
In Hellraiser, Frank Cotton's sadomasochistic love/hate relationship with the Cenobites and the Lemarchand Box makes him almost a textbook example of this type. He also at times appears to get a bizarre kick out of occupying the attic as a skinless, flesh-consuming monster which might suggest that there is a sadistic as well as masochistic side to his tastes.
And then there are the Cenobites themselves.
Pinhead: We have such sights to show you...
Especially in The Movie, The Addams Family considered their macabre surroundings normal. Gomez was implicitly a necrophile, and both parents were explicitly into bondage.
Along with S&M. "Ropes, red hot pokers..." "Later, my darling." Even the concept of dying doesn't seem to frighten them and when Debbie attempts to kill them in Addams Family Values they act sympathetic.
Morticia searches the impostor Fester's bag and remarks "Crowbar? Dynamite? Cyanide? Fester, as if we'd run out." Also the children are shown playing with weapons and even a working electric chair. Their parents give Wednesday bigger knives when they catch her with one.
It does have strong precedents in the TV series, in which they use a dungeon full of torture implements as a playroom. They cure headaches with a headvice, backaches with a bed of nails or the rack, and claim that an iron maiden is "relaxing". They even regularly wield medieval weaponry or, in Uncle Fester's case, a blunderbuss.
Harlen "The Reporter" Maguire in Road to Perdition. Not only is he a news photographer who specializes in crime scenes, he also moonlights as a assassin and takes a certain professional pride in his work.
To the extent that he considers a murder victim being Only Mostly Dead to be an unfortunate obstacle to a good photograph...
(asked if she worships Satan): I dated him once, but I wouldn't exactly call it worshipping....
(her trademark goodbye): Unpleasant Dreams!
The Jack Nicholson version of The Joker certainly is one of these when he meets Vicki Vale at the museum, reacting with bored indifference to (if not actually being turned off by) Vicki's modeling photographs, but being visibly impressed with (if not actually aroused by) her gruesome war photos.
Although it's somewhat justified by the fact that he defuses bombs for a living, Sargent William James of The Hurt Locker seems to enjoy playing with high explosives a bit more than can be considered strictly professional. And even the other bomb techs are a bit creeped out upon learning that he keeps souvenirs of every bomb he's ever handled in a box under his bed.
There are two twin characters from The House of Yes, Marty and Jackie, who like to have sex while reenacting the JFK assassination.
Jinya Yanase from Teito Monogatari Gaiden is a young hospital worker who's obsessed with the stories about Taira no Masakado and his Dragon, the Evil Sorcerer Yasunori Kato. He also happens to work in a mental hospital located near to the grave of Taira no Masakado himself, which fuels his imagination. Little did the guy know that he would end up as Kato's Soul Jar, though.
In Return of the Living Dead, we have Trash, who thinks a picnic in a cemetery is a fantastic way to spend an evening, and who becomes visibly aroused when talking about her idea of her worst way to die, to the points that she tears all her clothes off and dances naked in said cemetery.
In The Nightmare Before Christmas the entire population of Halloween Town is this way by default; it reaches the point of Blue and Orange Morality, since none of them seem to realize that kidnapping or poisoning would be unpleasant experiences for anybody else. So naturally, when they try to take over Christmas from Santa one year, the results are...a bit off.
Harry Potter's Hagrid is perhaps the most famous example. Hogwarts's Care of Magical Creatures teacher has a clear preference for dangerous beasts, including a Cerberus Captain Ersatz and possible descendant (Fluffy), a Norwegian ridgeback dragon (Norbert who's really a Norberta), a hippogriff (Buckbeak), and a giant fracking spider (Aragog).
Ollivander is another possible example; when Harry is fitted for his wand, Ollivander remarks with what seems to be almost pleasure that Harry has been selected by a wand which was made using the same materials as those used to fashion Voldemort's. Harry is understandably a little weirded out by this, and by Ollivander's next comment that he expects Harry to do great things, because so did Voldemort. "Terrible, yes - but great."
Most of the characters, in Andrew Boland’s novel Hells Children, are definitely Nightmare Fetishists. Going on the author’s biography, it would seem that he is one of these to, which would explain a lot.
Tommy in Bloodsucking Fiends. His first words after learning his girlfriend was a vampire? "That is the most awesome thing I've ever heard. Let's have sex with our socks off." The sequel gives us Abby Normal, a Perky Goth who didn't jump at the call to be a vampire's minion but hunted it down and demanded the job.
Vaughn, Ballard, Helen, and Gabrielle from J.G. Ballard's Crash. More so in the movie than the book, the whole plot seems to revolve around sexual fetishism involving grievous injury and automobile accidents.
Beth from the old Phyllis Reynolds Naylor books "Boys vs. Girls" was constantly reading horror books, but it made her a nervous wreck, while her drama queen little sister Caroline loved everything bloody and disgusting as long as it was dramatic.
In American Psycho, Patrick Bateman, a sociopathic serial killer mentions that he masturbates to a scene from the thriller film Body Double where a woman is drilled to death with a power drill. (Over the course of the book, he also tortures a woman with a power drill and does things that are even worse.)
Perdido Street Station gives us Mister Motley, a crime lord who spends a lot of time in the shadows. In the city of New Crobuzon, those who commit petty crimes are often turned into Re-Made by bio-thaumaturges, given animal or mechanical features that fit their crime. Motley has undergone this process voluntarily, hundreds of times, and now not only looks like a rolling mass of disjointed features, but has hired the main character's girlfriend to create a sculpture to his "glory."
And let us not forget the main character himself, Isaac Dan Der Grimnebulin. The aforementioned girlfriend is a shapely woman with a giant beetle for a head, he's extremely intrigued by Body Horror, a bird-person turning up on his doorstep asking for a new set of wings all but causes him to squee, and he is cheerfully enchanted with one particularly weird grub netted by his black-market attempts to find flight specimens. Until that grub grows up. You know when Isaac is freaked out, shit got real. He can hold a conversation, an intelligible and productive conversation, with TheWeaver.
Discussed Trope in A Song of Ice and Fire. The Mad King, Aerys Targaryen, had a fetish for burning people to death. His guard Jaime Lannister noted that it was only after doing so that he would visit his wife's chambers. And to add to it, he was so violent in bed with her that Jaime wondered if he was obligated to intervene.
Live Action TV
iCarly: The "Neck Infection" video elicits a Two Girls, One Cup reaction from Carly, Freddie and two other kids Sam shows it to, but she genuinely seems to get a kick out of it.
The Doctor has a tendency at times to happily wander into situations which horrify and disgust those around him and then, much to the confusion and bewilderment of his friends, cheerfully start pointing out things that he finds particularly interesting. The Tenth Doctor took this all the way over into the Nightmare Fetishist trope.
Good example from "The Girl in the Fireplace":
(The Tenth Doctor pulls the mask off a Clockwork Robot to reveal the inhuman workings underneath — everyone else recoils) The Tenth Doctor: Oh, you are beautiful. No, you are, you're gorgeous!
When the Doctor encounters a werewolf and it begins to break out of its cage, the look on his face is of obscene curiosity, even when everyone else is running in terror. (To be fair, it was a hypnotic werewolf.) Rose and the Doctor grin and hug over the novelty of being attacked by a werewolf when they get a moment to breathe in the midst of being chased by said werewolf. Queen Victoria berates the Doctor and Rose for their light-hearted attitude to horrifying situations, and decides to found Torchwood to specifically avoid that sort of thing in the future.
See also: The academic interest that the Doctor takes in the Midnight Entity in the episode "Midnight". A subversion, because the Doctor's merry interest in the thing makes everyone else terrified of him, nearly resulting in his death.
The Doctor and his companions have a general tendency to completely weird out anyone not used to their lifestyle, case in point being Rory in Vampires in Venice — particularly when they squee over the alien vampires on meeting up.
On Supernatural, Sam and Dean Winchester treat creepy, unnatural murders and monsters as ordinary occurrences. Every once in a while, one of them will Lampshade how weird their attitude and their lives are. Justified in three words "The Family Business", they were raised knowing what was out there and how to fight it.
Dean in particular is shown as being very excited when they get to hunt a werewolf, and at one point Sam gets him to come on a personal mission by promising that there will be zombies. There aren't.
Fringe has Dr. Walter Bishop, who doesn't bat an eye at events that disgust his teammates, and often displays genuine fascination and excitement when dealing with downright grotesque situations.
Count von Count from Sesame Street. Also, Oscar the Grouch, and the other Grouches by extention, in a different sense from the Count's.
Abby on NCIS. Given that she's a forensic analyst, this makes sense.
Also, Jimmy Palmer sometimes shows inappropriate enthusiasm for gory details. One example includes him cheerfully saying "At first we thought it was a serial killer!", another referring to the shapeliness of cut-off human legs. It's more disturbing in him then it is in Abby - in fact, in McGee's book the character "Pimmy Jalmer" was a necrophiliac.
Similar to the Doctor mentioned above, Firefly's River Tam is....well, curious about a lot of things. Like taking a nap on top of a coffin containing a corpse that wasn't really a corpse. Or watching her brother and the ship's mechanic have sex in the engine room.
Buffy and Angel: Darla and Angelus and Drusilla and Spike.
Giles' academic interest sometimes seems a bit too enthusiastic to others.
Giles: Grave robbing. That's new...interesting! Buffy: I know you meant to say "gross and disturbing.'' Giles: Yes, yes, of course. Terrible thing; must, must put a stop to it. ...ermh, dammit!
Chloe in Harper's Island has a very enthusiastic interest in serial killers, especially John Wakefield. In one episode she chose to go search through a forest to find a murderer's gravestone over partying at an open bar.
The eponymous Sherlock is sometimes portrayed this way. A self-proclaimed "high-functioning sociopath," he is genuinely fascinated and excited by morbid or disturbing cases, causing John to be occasionally horrified by his callousness. Unlike many of the other examples, this one is notPlayed for Laughs.
Despite John's status as Sherlock's Morality Chain of a sort, he himself is an example, being a Blood Knight who misses the violence and excitement of the Afghan war, which he was forced out of due to an injury.
The protagonist of Dexter is a serial killer who works for the police and gets fascinated with gruesome murders, especially in the first season.
One episode of Being Human introduces "Seven", a human who voluntarily acts a self-replenishing blood source for a vampire couple. Seven (and his six predecessors) are apparently all too happy to be fed on repeatedly and, when his "owners" intend to have another vampire drain him completely (ie, kill him), Seven is ECSTATIC.
That's Just Me has examples of this, being a disgusting and disturbing show, but the main character indulges in this. She's a sadist who's into BDSM and other weird fetishes, including the one that inspired most episodes, her vomit fetish. However, she claims that she's harmless because she's into animated cartoons of this stuff and doesn't intend to do it to anybody in real life.
She also wants to be abducted by aliens, have an out of body experience, talk with ghosts, stay in a haunted house, and do all kinds of other paranormal things and act like it's totally normal.
Emilie Autumn is probably one of these, considering the subjects of most of her songs and the stories she creates in her concerts, songs and now a book about a Victorian Bedlam House for little girls.
Gore-related lyrics in Death Metal or goregrind. Most of us find the idea of knives being repeatedly inserted into human vaginas and used as sexual aids deeply distressing: Cannibal Corpse apparently find it amusing.
The Gothic Archies' "Walking My Gargoyle" is about an eccentric man's love for his pet gargoyle.
Many of The Misfits' songs fit into this category, especially "Last Caress" (about killing babies and raping mothers) and "Bullet" (about JFK's assassination and treating his widow as a sex object).
A good number of Rasputina's songs treat dark subject matter, but most aren't treated in this fashion. However, the glee that is expressed at the idea of pumping holy water into the anus of a possessed man in "Christian Soldiers" and at the idea of cannibalism among the Donner Party and colonial Pilgrims in "The Donner Party" do delve into this territory.
Evanescence: Opinions differ but they put some sexy riffs behind songs about death and and horrific circumstances. Just check out Tourniquet and The Other Side.
Perhaps the most chilling of all Calvin's fantasies had his parents clucking over him delightedly as he plays with his Tinkertoys ("He's creating whole worlds over there") - without knowing that their son is imagining that he is the god of his own private universe and enjoys sending mortals to Hell. Bill Watterson's lurid drawings do not help.
A classic Charles Addams cartoon shows a movie audience all with somber, teary-eyed faces... except for Uncle Fester, who's grinning delightedly.
Exalted players have a joke. Everyone Is Bi, to the point that considering a homosexual relation to a god made of goo is commonplace. If he's hot enough.
This is the norm in Mortasheen. Consider that this is considered the city's "Handsomest Theoretically Male Organisms" and that's not as much of an Overly Narrow Superlative as you might think. Of course, given that the guy behind Mortasheen also runs Bogleech (See below), this shouldn't be much of a surprise.
Slaanesh followers. If it exists, they will find a way to derive pleasure from it. It isn't necessarily sexual pleasure, but that tends to be the most common. They take this trope very literally.
Dark Eldar are almost as bad as Slaaneshi cultists, revolving their entire society (if it can be called that) around inflicting extensive and painful tortures on anyone they can capture. While they're essentially forced to do this, otherwise they have their souls eaten by Slaanesh, they make no illusions as to how much they enjoy it.
Creatures like dragons, demons and the like are often repulsive, but, as have been proved repeatedly, humans will screw or be screwed by practically any kind of monster at one point or another.
With Yawgmoth and Phyrexia destroyed once and for all, the Glistening Oil left in Karn has taken over his beloved Mirrodin. And his mind. With the five suns of Mirrodin, the previously Monoblack (and Artifact) Phyrexia is now split into the five colours. WhitePhyrexia's stated goal is to bring the glory of New Phyrexia to the rest of the Multiverse. They have a severe dermatophobia, emphasized by taking the new recruits, flaying their skin, and stitching them together.
White Phyrexia is also known for wearing cracked porcelain masks and carapaces, said to be stronger than steel. These bits of porcelain◊ are made from dead Mirran that didn't make the cut.
More than one Prestige Class from Dungeons & Dragons tends to attract these types. Complete Arcane has the blood magus, who really enjoyed the sound of his blood flowing when he came back to life, and can do things like store spells in his scars and blood or teleport between two living creatures through their blood. It also includes the alienist, who's made contact with Things Man Was Not Meant to Know. The fleshwarper from Lords of Madness does the alienist one better, deliberately altering himself with Mad Artist glee, and eventually turning into an aberration. Sea witches from Stormwrack delight in the power of the storm. The best part? All of those classes are open to good characters.
Bad Powers, Bad People examples include the walker in the waste from Sandstorm, who loves the clean beauty of the desert and works to share it with the world. The Book of Vile Darkness, unsurprisingly, has several: the cancer mage with his tumor familiar, the vermin lord with his armor made of living bugs, and various flavors of demon- and devil-worshippers.
Katisha from The Mikado (and Ko-Ko, depending on how "There Is Beauty In The Bellow of the Blast" is played).
Vincent, one of the supporting characters in , eagerly describes the rusted, blood-splattered nightmare world around him as "fascinating", and briefly claims to be confused that the grotesque creatures the protagonist has been fighting throughout the game "look like monsters" to her. But then again, we never quite know if he and the heroine/player are seeing the same thing.
Claudia, who explicitly refers to aforementioned rust-and-blood-stained nightmare as a "paradise" and endeavours to have it spread over the entire planet.
Heather also voices an interest in things that deeply horrify normal people. Then again, she is Alessa Gillespie, so a bit of an interest in the dark and disturbing is pretty much mandatory.
Pokemon Diamond And Pearl has an NPC in Hearthome City complaining about Amity Park, a park which allows only "cute" Pokémon, discriminating against his Steelix and Gyarados.
As a child, Kelda from Overlord II thinks the sinister Creepy Child Witch Boy is cute and interesting, and gleefully helps him hunt down and destroy the children who tormented and bullied him, then destroy the Winter's Eve festivities, despite not being particularly evil herself. Her attitudes don't change much once she grows up, even talking about how she hates her town for their treatment of her childhood friend, now an Evil Overlord and her lover.
Metal Gear Solid brings us Volgin, Vamp and Ocelot, all of whom could probably orgasm purely through the act of hurting someone.
In Thief, Garrett only ever really shows any sort of romantic attraction to one person who can only really be described as horrifying even when naked. A wood nymph named Viktoria who ripped his eye out in the first game.
Selphie in Duodecim thinks the way the insane roaring four-armed demon monstrosity Feral Chaos runs around on all fours is "kinda cute", although she's always been shown to be weirder and crazier than Penelo.
In Dead Rising, Kent the photographer has an edge of this plus Mad Artist - the first time he runs into Frank and shows off his photography, he sounds absolutely riveted while showing off his "most violent shot!", and from there, it only gets worse and worse. The next time Frank encounters him, depending on his arrival's timing, he'll be keen on either photographing a human transforming into a zombie or stripping Frank down to his briefs, slapping a spiked collar and chain on him, and watching him get torn limb from limb by the undead and seem really excited about it. Of course, he ends up being one of the game's Psychopaths.
Both Kent and Frank are literal examples, as the game rates your zombie photographs for "eroticism" and Frank will lecherously cheer if you manage to get a Panty Shot of a dead woman.
Leanne was raised by a Torture Technician who kept her isolated from other people. Consequently, she loves the smell of blood and sound of screaming as reminders of her only parental figure. Unusually for this trope, she's neither comical nor monstrous, but psychologically damaged to the point of being a borderline Woobie.
Demon's Souls: The Maiden in Black, a creepy and powerful demon who has wax permanently fused over her eyes. This hasn't stopped the questionable fanart, though..
Star Fox: Leon Powalski has a rather distinct fascination with very specific aspects of Star Wolf, given the Smash Taunt in Super Smash Bros. Brawl. Panther Caroso practically calls out on him. The voiceover gives far more impact than plain text..
Star Wolf is really giving it his all out there. I'm more than a bit envious of him. Those razor-sharp claws. Those keen fangs. He moves wildly and fights with the spirit of a warrior possessed. Any prey he sets his eye on is doomed to be shredded to pieces.
Tira from the Soul Series is literally a Nightmare Fetishist. She is absolutely devoted to Big Bad Nightmare, the monstrous embodiment of Soul Edge itself, whom she sees as a kindred spirit. In the fourth game she doesn't even really mind that Nightmare will likely eventually consume her soul; she is that loyal to him. In her ending, she is distraught when she realizes that Nightmare's body can no longer withstand his own power and clings to him while desperately begging him not to leave her alone. She gets her wish in a way when the remnants of Soul Edge's power joins with her.
Corpse Party: Blood Covered has a particularly creepy example in Sakutaro Morishige, who seems completely normal before The Reveal. Said reveal comes about when you discover him blushing and gushing over the smeared remains of his best friend's corpse, filming it on his cell phone. Of course, he doesn't know it's her at the time and does not take it well when he finds out. Ayumi Shinozaki is a subversion. She loves telling scary stories. Being in a scary story? Not so much.
Knowledge Aspiration sims in The Sims 2 often want to be abducted by aliens, have near-death experiences, become vampires or go through other paranormal experiences other sims dread.
Henry in Fire Emblem: Awakening. Almost everything he says has him squealing in delight, to the point he drools when thinking about blood.
You can be this in Hatoful Boyfriend by pursuing a romance with Dr. Iwamine Shuu all the way to the bitter end.
In Touhou: Phantasmagoria of Dim. Dream, a scientist from another universe travels to Gensokyo to capture one of the magical denizens to prove the existence of magic to her peers back home. As a player character, her victory quotes are often delighted by the supernatural entities she's encountered.
Yumemi: Oh, a real evil spirit/ghost/witch/shrine maiden? How marvelous!
In Mass Effect 2, the game seems to repeatedly imply that Harbinger is ridiculously preoccupied with trying to capture Shepard, in order to understand why they are able to repeatedly thwart the Reapers and how a single human can possibly be so dangerous! Indeed, most of his dialogue implies that instead of killing Shepard, he actually wants to keep them for study or make them into an indoctrinated figurehead like Saren.
Shep his/herself can show shades of this; conversing with Jacob and Miranda about the acquisition of a krogan in a cloning tank, s/he can be outright gleeful about the fact that none of them know what this krogan is like. In the Mass Effect 3DLC "Leviathan", s/he can decide to take the severed animated head of what is either a Husk or a Cerberus trooper back to the Normandy to be installed in his/her cabin, at the suggestion of James Vega, who loves that thing even after it bites him.
In the second game, Shepard retrieves their N7 helmet from the wreck of the first Normandy and Liara later gives them back their original dogtags. So basically, Shepard enjoys decorating their cabin in things they were wearing when they died!
The helmet is actually pretty understandable considering it kept Shepard's brain intact, leaving him/her Only Mostly Dead instead of completely so.
In Golden Sun: The Lost Age, Kraden's reaction to seeing a werewolf near Garoh is pretty much pure Squee, and he demands that the (alarmed) player characters look for more, while insistently denying that he's excited to see werewolves.
"All right, so I lied! I'm glad we found werewolves! Are you happy?"
He's also fascinated by the dangerous Psynergy Vortexes in Dark Dawn.
Kormac: When I became a Templar, I dreamed of invading the Hells themselves. This is all I ever wanted.
Witch Doctor: Sometimes, you worry me.
Shuinji Watanabe from Sexy Losers. In the beginning, he was "just" a necrophile, but he was flanderized into being a fan of zombies, amputees and flesh wounds. Other characters of the webcomic apply too.
Bugbears in Skin Deep basically exist to find people wherever they are and scare them. A character even describes that some of the the real life examples here are bugbears in universe.
Yuki from MegaTokyo. She has her very own pet zombie godzilla (Zom Zom-chan) which she tries her very best to make as kawaii as possible.
Tsukiko from The Order of the Stick. The first time she met the lich Xykon, she hit on him. (Later, she's seen carrying around a Xykon doll.) She also acted like a mother to a group of wights she had raised, stating that 'a pulse is not a prerequisite for being loved.'
In Drowtales, Mel creeps out even other drow with her love for spiders.
Rose Lalonde from Homestuck studies the zoologically dubious in her spare time, preferably in her trusty grimoire. Not to mention her chumhandle, "tentacleTherapist". Given her penchant for psychoanalysis, it's most likely that it's intended to be read as "tentacle Therapist", not "tentacle The rapist", but either is pretty Nightmare Fetishistic.
Feferi really doesn't understand why Jade (along with most of the readers) was so freaked out by the Gods of the Furthest Ring. Although this is justified, seeing as her guardian lusus (parental figure) was their emissary, so she's quite used to seeing mind-warpingly bizarre Cosmic Horrors by this point.
Aradia, after her ascension to God Tier. She honestly doesn't see why others are creeped out by her eagerness to throw a "corpse party" (read: funeral) and sees death as something worth celebrating.
Sparks in Girl Genius have a disturbing tendency to get fired up when discussing any kind of experiments. The more gruesome, twisted, dangerous, or unusual the experiment the better! Also, this:
"Not a bad idea, but d'Omas' taste in women was... well... let's just say it was lucky for him he could build his own. There'll be no d'Omas heirs showing up... except in glass jars."
Amusingly, the third panel now has dialogue. In the original, it was silent — they mentioned in a podcast that they had to add it because without the dialogue, it pushes it past "funny" and into scary.
Elmsly from Beyond the Canopy. He's excited about visiting a swamp full of poisonous wildlife, and after Glenn defeats a group of dangerous spider crabs, Elmsly wishes he could have studied one of them up close.
Similarly, we have Bennett the Sage of Masterpiece Fanfic Theater, who reads fanfics that tend to reach Nightmare Fuel levels of Squick. Sure enough, he appeared alongside Ask That Guy...and proceed to horrify him.
Let's not forget Ralph, the Inner Serial killer dwelling within Luke Mochrie's mind.
Ralph: When I know there's going to be violence involved, I always, always make sure I have a bottle of lubricant and some paper towel on hand.
The Nostalgia Chick is an expert on all kinds of disasters and glees over Disney being "a veritable treasure trope of gruesome ways to die".
Anna Chase of Survival of the Fittest v4. She is a complete and utter aversion of Girls are Really Scared of Horror Movies. She seems particularly fond of psychological horror and slasher movies, and can be described as a bit obsessed over them at times. It has been shown that on a couple of occasions, if something reminds her of a horror movie she could easily have a "Cool!" type reaction, though not always. Occasionally, this, combined with her normal personality, sides into Nightmare Fuel Station Attendant tendencies, as you might expect.
In another example, the Big Bad, Danya, also appears to be an example of this trope, as although he has an agenda to his actions, he seems to genuinely enjoy watching teenagers killing each other, for the most part. In fact, a good portion of the time he is cackling over how so-and-so died that day whenever announcements come up, often poking fun at the victims. He also reads SOTF fanwork for fun. Speaking of which, the program in-universe does have people who watch the show, even if a Guilty Pleasure interest in it, including a number of characters that appear on the island.
Carmilla of the Whateley Universe. Hawthorne dorm residents were horrified when she went down to the dorm's deepest level into a room you aren't supposed to enter and faced the unnameable horrors inside. She treated it like a big party. But then, she is an Eldritch Abomination herself.
Ed from Nullmetal Alchemist is one of these, referring to his revived mother's horrifying fgure (noting that she's mostly organs) as beautiful and has a long discussion with a serial killer about how fascinated he is with the grotesque. Al comments on how he doesn't want to discuss Ed's "nightmare fetish".
After hearing Al's justification for staying a suit of armor (to be attractive to Winry):
Not even Disney shies away from this trope. Lilo & Stitch's Lilo practices voodoo, owns a handmade doll that she pretends has a bug-infested skull, and is generally considered a freak by her peers. Her only true friends turn out to be from outer space.
In Lilo And Stitch The Series, she did make friends with another, similar human girl. Lilo gave the girl a pet alien experiment shaped like a bat who ate mucus to help her with her sinus problems. Really.
As mentioned in Film, Lydia in the 'toon versionBeetlejuice not only became friends with the gentler (but still revolting) Beej, she's been shown to own spiders, and everything she does from starting a band ("The Brides of Frankenstein") to designing Shakespearean costumes (which got Ol' Will's thumbs up of approval) have strong Gothic undertones. Nevermind that she does happily shunt off to the Neitherworld.
In the Where's Waldo? cartoon, actually called Where's Wally?, the title character will constantly and cheerfully remark on their current plight; for example, falling hundreds of feet "to certain doom!"
He also smiles constantly while watching others get pummeled or is in danger of a pummeling himself (said eagerly: "Who's the menacing fellow who looks as if he'd like to twist me into a knot and throw me off a cliff?"), is excited to be standing in front of an angry stampede, be attacked by monsters, be tied up in chains, be taken prisoner ("Wow, Woof, didjya hear that? We're official prisoners!"), hop into a dangerous pit of doom (shaking bag and smiling: "Well, Woof, apparently I didn't bring my parachute."), and is nothing short of thrilled to be in a cave-in. ("Wow, Woof! It's a real cave-in! And we've only been here just a few minutes! (elated sigh) How lucky can you get?") Seriously, how did Woof survive being around this guy?
In Growing Up Creepie, Creepie Chreecher falls in love with a boy working at a carnival who she believes is half-tarantula, but loses interest when she finds out it was just a costume. In a later episode her interest in him returns once she finds out his adoptive mother is a giant spider.
Most of the cast of Superjail seems to be this trope. Even Jared, occasionally.
Raven of the Teen Titans displays some morbid inclinations, has been described as "way creepy" and... should the world get turned into gothic ruins and blood red sky? "Cool." Of course, in this case it's hard for her to help it, since she is the daughter of a demon after all.
Very, very little fazes The Magic School Bus' Ms. Frizzle if it can be used as a teaching moment. Moments like getting ensnared by a giant spider, getting eaten by a student, and falling into a volcano.
Dr. Potterswheel from Moral Orel is sexually aroused by lacerations, scars and disfiguration. He accidentally killed his wife by loading her full of painkillers after an accident rather than actually treating her wounds. It's possible that this could still happen to Bloberta, who spent entire days mutilating her own vagina to seduce him. Keep in mind, absolutely none of this is Played for Laughs.
Well, it's Played for Laughs a little bit. After all, she does use a jackhammer... They just make up for it by emphasizing how unhappy she is.
Cheryl: You seriously don't think that's hot? Pam: I seriously think you're scary. Cheryl: No, nononono. Like, a big sweaty fireman carries you out of a burning building, lays you on the sidewalk and you think "OK, he's gonna give me mouth to mouth," but instead, he just starts choking the shit out of you, and the last sensation you feel before you die is that he's squeezing your throat so hard that a big glob of drool slips right off his teeth and -* blurp* - lands right on your popped out eyeball. (beat) Pam: Jesus Christ! Cheryl: I know, right? Lana: What the hell?! Cheryl: I'm wet just thinking about it.
Krieger as well.
Archer: Wait, are you still taping bum fights to get off?
Krieger: No, now I'm into something much... Darker.
Cheryl and Krieger dated for a while, until she left him because he was too weak to strangle her and the "robot choke arm" just wasn't the same.
Cheryl: I'm sorry, but your hands are just too tiny and weak. It's like being strangled by a child, which I thought would be hot, but it wasn't!
Edith from Despicable Me. Her bedtime prayers include the request to not let bugs go into their ears and lay eggs in their skulls/brains, she finds it "cooool!" that she and her sisters are sleeping in old, inactive bombs after Gru adopts them, and she is extremely excited to see that her pancake is shaped like a "dead guy."
Heloise from Jimmy Two-Shoes actually becomes depressed when there's destruction and she's not the one causing it.
Then in Bend It Like Wreckem; after Jimmy and Beezy accidentally knocked the pro soccer player Wreckem out, she takes his brain out and takes care of it, then hugs it while baby-talking it!
Phineas, of all people, from Phineas And Ferb could be seen as one. He's highly enthusiastic about almost everything, including things that would scare your average person (this side of him was definitely on display when he and Ferb built the haunted house). Not to mention that he delivers lines like this in his usual gleeful tone:
"In case we capsize, your seat cushions can function as a headstone!"
Marceline: The only thing women love more than fun is excitement. She needs to feel her blood pump, man! She needs to...BE CHASED BY WOLVES!
On Gravity Falls,Dipper tries to convince his sister Mabel that her new boyfriend is a zombie. She's mostly just excited by the idea that he might be a vampire instead. They're both wrong—he's five gnomes in a costume.
Just check out the Bogleech website for some excellent examples of a guy waxing poetic about hagfish.
Robert Young Pelton has made a career because he loves going to the most miserable places on earth and living there. Most of this favorite vacation spots can be found by looking at list of the most violent conflicts of the last couple decades.
Teratophilia is the sexual attraction to deformed or monstrous people.
Anybody who studies/is fascinated by things that cause phobias in most people - like spiders, snakes, sharks, bees etc.
This is most often because of the fact that said people realize something: most of these animals aren't actually harmful, and are often quite beneficial (at the very least, at population control). Without bees pollinating crops, for example, the world would be without a huge fraction of its food.
Junji Ito, the disturbingly enthusiastic horror mangaka.
Go to a movie theater to see a horror movie and chances are that at least half the people there to see it are there (at least partially) for the Nightmare Fuel aspect of it.
Arguably this is the entire point of the Horror Genre.