Perpetual Smiler

"Koizumi's cheerful smile pisses me off every time I see it."

—Kyon's narration, Remote Island Syndrome

"Buena Girl's parents scare The Flea; they are so... happy."

—The Flea, Mucha Lucha

The exact opposite of Perpetual Frowner. This is a character who, no matter what, is never seen without a smile of some kind. A Stepford Smiler would be a sub-trope, one who smiles because that's all they can do to keep from breaking. A Cat Smile or Cheshire Cat Grin can also be their perpetual expression. A Perpetual Smiler's smile can change, and the emotions behind it can be literally anything... so long as there is something that can be called a 'smile' on their face. Usually, though, this smile is pleasant and cheerful, or at least calm, and often, the feeling behind it is genuine, so The Un-Smile doesn't usually appear. Compare to Glasgow Grin, where the smile is ear-to-ear and usually inflicted by cutting.

As a Super-Trope of those listed above, all examples of them should be sorted into their respective categories. This page is only for examples of this trope who do NOT fit into the other perpetual-smile categories.

Examples of Perpetual Smiler include:

Advertising

Jack the Clown in the "Jack In The Box" TV commercials, who's been appearing as a living, ball-faced humanoid since 1995. It disappears when he's particularly perturbed, though.
Smilin' Bob from the Enzyte commercials. His smile is particularly creepy...

Anime and Manga

Sendo from Slam Dunk is considered as this.
Kamui from Gintama. Even while killing everyone during the Yoshiwara arc.
Kasumi Tendo is never seen without a lovely smile, and doesn't seem to have Stepford Smiler tendencies.
Despite the fact that he really doesn't understand emotions, Sai from Naruto is a Perpetual Smiler. He has reasons for this though, which do not fall into the other categories.
Wolfgang Grimmer from Monster doesn't even stop smiling as he bleeds to death. He is a pleasant person but the smile is just something he was trained to do.
Konata Izumi from Lucky Star has a Cat Smile that, while not quite perpetual, is her default expression.
Raquel from Scrapped Princess is perennially cheerful no matter what's going on.
Itsuki Koizumi from Haruhi Suzumiya.
Ichimaru Gin and Sousuke Aizen.
God from Oyasumi Punpun
Elmer C. Albatross of Baccano! is always smiling and happy. He'd be The Messiah were it not for the fact that there are times where one shouldn't be smiling and jokey, so he just comes across as creepy. Oh, and he's friends with Huey Laforet.
Professor Souichi Tomoe of Sailor Moon S. Heck, for most of the series, the only thing we ever see of his face are his Scary Shiny Glasses and his big, open-mouthed smile.
Jail Scaglietti of Magical Girl Lyrical Nanoha Striker S is another perpetually happy fellow. Impending defeat and imprisonment couldn't even make him drop his smile.
Kaede of Mahou Sensei Negima is always smiling mysteriously, to go along with her Eyes Always Shut. She isn't actually very mysterious as a character, having no secrets to hide, she just looks it. Unless she's so good at hiding secrets that we don't even suspect them.
- ~~Albireo Imma~~ Ku:Nel Sanders also has a perpetual Cheshire Cat Grin, although he's generally much more suspicious than Kaede.
Ryuk from Death Note. It's creepy. He only broke it once when Light snapped at him after Offering the eyes after meeting L.
D.Gray-man has the Millennium Earl, who smiles even when he's pissed.
Kousaka from Genshiken, always has the same expression, no matter what takes place.
Xellos from Slayers.
Yamamoto Takeshi, for the most part. When he stops smiling though, you had better start hoping you can run faster than the baseball player, because you're about to get screwed over epically because Yamamoto is ticked off.
Pride, PRIDE, OH DEAR TRUTH/GOD/ANYTHING PRIDE!!!!!!!!!!!
- Also, Ling Yao.
Ariel from Kore wa Zombie Desu ka?.
Mikako from Sora no Otoshimono.
Ling-Ling from Rosario + Vampire. Justified, since she's already dead, and thus has nothing left to worry about.
Kyuubey, anyone?
Ojisan of Yokohama Kaidashi Kikou is always grinning.
Thailand from Axis Powers Hetalia
Kio from Loveless.
Koala from One Piece, until Fisher Tiger broke down her Stepford Smiler façade.
Hao Asakura from Shaman King. And his twin Yoh, to a lesser extent (his smile is more genuine).

Comic Books

The Joker, obviously (his appearance was based partly on the Laughing Man).
- Well, make that every incarnation of the Joker except Heath Ledger, who has a Glasgow Grin.
Also from the DCU, The Creeper.
- There's also Mad Harriet who's smile is quite similar to the Joker.
For the first portion of his appearance in Transmetropolitan, Presidental candidate Gary Callahan is one of these. That's why they call him "The Smiler" (also to contrast with incumbent "The Beast"). He rapidly loses the quality once he starts dealing with Spider Jerusalem.

Film

The Smiler from Transmetropolitan. He must be under great pressure before the raised corners of his mouth even twitch.
The Man Who Laughs (L'Homme Qui Rit) is a man who literally cannot stop smiling as he has no cheeks (he was kidnapped by gypsies as a baby, who mutilated him like this to make money showing him off). His picture currently illustrates the Slasher Smile page.
The Piraka and their whole species in Bionicle.
Westley from The Princess Bride only stops smiling once he's dead. Of course, he gets better.
- Actually, he didn't smile in flashbacks, either. He was being too serious about his love for Buttercup.
Michael Sheen's portrayal of Tony Blair in The Deal and The Queen covers just about the whole range of possible smiles, to the point where it starts to feel like his teeth are following you around the room. Which is pretty much Truth in Television.
Most of the toys from the Toy Story series are this in their 'toy' mode.
Atom in Real Steel. His face (if he has one) is obscured by a metallic mesh that only shows his eyes, but there are seams in the mesh that resemble a nose ridge and a smile. It helps highlight his child-like appearance, which is most noticeable when his Shadow Function is activated.

Literature

The Cheshire Cat and his trademark grin.
Ella in Sunny Ella, though what kind of smile it is changes depending on whose point of view we're reading.
Jon Masters from Dale Brown's books.

"The bastard never stops smiling, too. You notice that? Always with the damned grin on his puss. I don't trust somebody who grins all the time - it usually means they found someone else to put the blame on."

Live Action TV

The Gentlemen from the Buffy the Vampire Slayer episode "Hush"?

Toys

LEGO minifigures, usually.
- The older kind more so; newer ones (from around the mid-to-late nineties on) have plenty of frowns, neutral expressions, and other miscellaneous emotions to perpetually display. Some of their heads can be turned around for different expressions.
- Within that, Flex from Alpha Team is said to always smile "even when danger threatens".
- A Robot Chicken sketch lampshaded this to creepy effect by depicting a spaceship accident resulting in the astronauts inside burning, their faces still stuck in Perpetual Smiler mode while screams were overdubbed. Despite the sketch's Black Comedy, it crosses into nightmarish, especially when one of the firemen yells "Their faces! Their horrible faces!" before another cut to them smiling/screaming.
Barbie.

Video Games

The Kid from I Wanna Be the Guy is forever grinning ecstatically, in contrast to what one might expect from someone who is rarely more than a few seconds from death.
Maxwell in Scribblenauts is always smiling, even when he's getting eaten alive or otherwise mauled.
Evil Otto in the early 1980s arcade game Berzerk, who is basically a smiley button, who comes onscreen to chase after the player and to electrocute him, passing through walls and destroying robots along the way. On top of that, he's also invulnerable. Designer Alan MacNeil put Evil Otto in the game because he hates smiley buttons.
- Evil Otto also appears in the game sequel Frenzy, but he loses that smile when the player can now shoot him down.
Metal Gear Solid 3: Snake Eater the Sorrow is always seen smiling.
Inazuma Eleven's 3D character models have fixed expressions. Characters who smile will smile even though the ball hits them. Masaru Gojou always has a rapist's face, and Hijikata will never stop grinning.
Sunshine is constantly seen smiling in Kinnikuman: Muscle Fight. His super meter even has a depiction of him smiling. The only times when his expression changes is when he gets hit by the Cross Bomber, does that super where he freaks out about Friendship Power, or when he loses.

Web Original

The Comics Curmudgeon describes TJ from Luann's smile as a death-rictus.
80's Dan is almost always smiling and cheerful, especially when he's taken a good hit of cocaine.
Cedric Diggory in A Very Potter Musical.

Web Comics

Trudy of General Protection Fault is one, combined with Bitch in Sheep's Clothing. As such, her "Nega" counterpart is a Perpetual Frowner.
Coyote from Gunnerkrigg Court, who has a near-perpetual Cheshire Cat Grin. Even on the rare occasions when it vanishes, though, his upbeat attitude never does.
The Caped Crustacean from Beyond the Canopy seems to have a grin permanently on his face. As it turns out, he's just wearing a smiling mask.
Smiling Guy from Power Nap, who smiles even as he is kicked out of the way and his desk set on fire.

Western Animation

A number of the Mr. Men and Little Misses, but especially Mr. Tickle, Mr. Happy, and Little Miss Sunshine.
The eponymous Ruby Gloom since she always looks on the bright side - in direct contrast to her aptly-named friend Misery.
Most of the hero characters in the Rankin Bass Stop Motion Christmas specials had built-in smiles, which made it unsettling when they had to be angry or sad.
Phineas from Phineas and Ferb rarely changes to any other expression - in the whole series, he was only truly sad during the Christmas Special, and once angry and frantic in Summer Belongs To You!. Isabella could count, too, but she's more prone to expressing anger than the eponymous Every Man.
In the cartoon of Where's Waldo, Waldo almost always smiles.
The Joo Dees from Avatar: The Last Airbender are Brainwashed to do this.
Ed the hyena from The Lion King is always smiling the only instances he doesn't smile is when he's trying to warn Banzai and Shenzi that Simba and Nala are escaping and later when hears Scar outing them as the reasons why he's evil.
Nick from Invader Zim. The happiness probe may be involved.
"Cindy", "Bianca", "Hi me", "Iria", and "Zade" from "Little Princess School" for some reason never. stop. smiling.
My Little Pony Friendship Is Magic has Pinkie Pie, who is always smiling save for a few... notable exceptions.
Galaxy Rangers: Zozo is a very cheerful and laid back guy, even in the middle of a brawl with guys twice his size. It's not like he can't stop smiling, it just takes a lot for him to choose not to.
Whatever he's actually feeling, Bull Gator is, in verbiage and tone, almost invariably cheerful and collected about the situation. Even when he's facing down a Tasmanian Devil who regards mauling him as good, clean, Sunday-afternoon fun.

Real Life

This is a symptom of the Angelman Syndrome, a genetic disorder characterized by development delay, speech impediment, movement or balance disorder, and frecuent laughter and smiling.