The past 20 years or so have seen a surge in the popularity of evil, Joker-style Monster Clowns who deliberately and very effectively invert everything clowns were traditionally assumed to represent - that is, making people laugh, especially children. However, there was a time when clowns were treated in the popular media as sympathetic figures of whimsy and silly fun. Outside of their early habitats like rodeos and circuses, pretty much the only clown left in the public eye who is still permitted to act at all clown-like is Ronald McDonald. (And now he's allegedly being phased out of the advertising.) But in days past...
For clarification, it should be noted that a degree of irony is intrinsic to most clown performances, and indeed to humor in general. The traditional "tears" painted on a clown's cheeks are there to show that he is laughing on the outside but may be crying on the inside, an acknowledgment by the performer that most humor contains at least some element of laughing at another's pain. This is most played up in old-school, down-on-their-luck "hobo" clowns like Emmett Kelly Jr., though the ultimate artistic expression of the tragic clown concept is probably the title aria in the opera Pagliacci. The "Non-Ironic" in the trope's name simply refers to the clowns listed here not being evil or deliberately frightening. The fact that a clown even has to be identified as "non-ironic" is pretty telling.
See The Jester for a more common type.
In the mid-80's, Circus Fun breakfast cereal's mascot was a clay animation clown and his animals.
Batman #528 has yet another tragic, "life's loser" clown that works at a barely-surviving circus. He manages to disrupt the Mexican Standoff between Batman, Two-Face, and the circus' corrupt owner by releasing a lion from its cage, and later informs Batman that he had seen said owner murder his uncle, the circus's previous owner, by loosing a tiger on him. His reason for not revealing this to the cops? He feared that the circus would be shut down, and since he has no savings and few job skills... After reflecting on this for the better part of a few years, however, and getting a chewing-out from the Dark Knight, he decides to go and testify to the cops after all. (For extra irony points, the case was one of the many "ghost files" that Two-Face possessed back when he was still District Attorney - he knew who was responsible, but couldn't prosecute as he had no evidence).
The clown at Haley's Circus is a recurring character in the New 52Nightwing. He's a bit cynical, especially about working in Gotham; Gothamites tend not to be fond of clowns.
Jack-in-the-Box is an interesting case in that, depending on the story, he falls under both this trope andMonster Clown. While Jack-in-the-Box is a fundamentally good person, he's not above using the clown gimmick to scare criminals. Further, his successors Jack and Box are genuinely freaky.
The heroic White Clown of Borovia from one G.I. Joe story arc.
Ponyacci, meanwhile, is actually something of a Sad Clown during his stories — literally; he doesn't act a clown to hide how sad he is, he's a clown who loves being a clown and is sad that old age is forcing retirement on him. With Pinkie Pie's help, however, he's able to open a school for more non-ironic clowns and resume his former happiness.
The clowns from Disney/Dumbo were rather unsympathetic and mean-spirited when out of character, though this came from their stupidity, not their clownish nature. But during their performance, they were very enthusiastic about getting laughs from the audience. One of the clowns does seem to show at least some sympathy for Dumbo, though. However, the other clowns will have none of it:
Sympathetic clown: Be careful, you'll hurt the little guy. Unsympathetic clown #1: Aw, go on! Elephants ain't got no feelings! Unsympathetic clown #2: No, they're made of rubber!
Zip from Rock and Rule was a fan of the in-universe cartoon "Uncle Mikey's Cow-toon Show", starring a clown named Uncle Mikey. While Uncle Mikey was ugly-looking and his choppy animation could have made him rather disturbing to watch, he was actually a sweet character who tried to teach children the difference between good and bad.
Film - Live Action
Phroso the clown in Freaks is a textbook example — works hard on new gags for his act, a friend to all the sideshow folk, kind to the pinheads, develops a truly sweet romance with an animal trainer — really a heck of a guy.
Harpo Marx's persona had most of the characteristics of a clown, if not the face paint.
Charlie Chaplin's The Circus, featuring Chaplin stock player Henry Bergman as an entirely non-ironic clown.
Helmut, from Jim Jarmusch's Night on Earth, the taxi driver used to be a circus clown in East Germany.
Louison in Delicatessen used to be a clown, but he quit when his chimpanzee partner was eaten.
Babe: Pig In The City has Fugly Floom, a kind elderly clown who does shows for children in hospitals despite his failing health.
Helena's family's circus in MirrorMask features several clowns, who are friendly and likeable both in and out of makeup.
Russian kids' green screen show Komedya Klowna (??????? K?????) (mostly) features these.
JP Patches, who to this day, decades after his show was cancelled, he still performs as his clown character.
Barnaby, an English sheepdog in a bowler hat and baggy pants who regularly performed on Disney's Dumbo's Circus. He was shown to be friendly if kind of stupid, and he was actually more of a jack-of-all-trades than a clown, also performing magic and the like.
Justin Fletcher's character Mr. Tumble on The BBC's Something Special is an old-school physical clown.
One of the titular "Five Characters in Search of an Exit" from The Twilight Zone is an interesting take on this trope. He's not scary in any sense of the word—but he is extremely cynical and borderline depressed, making darkly humorous comments about the group's situation and occasionally breaking down, revealing that he's just as frightened and confused as the rest of the four.
The Billy Joel song "Lenningrad" tells the story of Viktor (an actual person whom Joel met while touring the Soviet Union in 1987), a former member of the Red Army who, after seeing the horrors of war, became a clown, and found happiness bringing joy to children.
Despite the edgy name of Psycho Pinball, there's a totally harmless clown prominently featured on the "Psycho" table.
All Japan Wrestling's Piko, more commonly known as Command Bolshoi, is fun, not evil and no attempt made to make her look scary but she is among the most competent veterans on the roster and as such, not the butt of many common clown jokes.
Originally, Doink the Clown was portrayed as a sadistic and tricky evil clown. He eventually turned a new leaf and tweaked his pranks to be less cruel and more comedic.
The tragic clown opera Pagliacci (although it must be said that, even if nobody in it is a modern "monster clown" psycho, none of them are nice people).
Cirque du Soleil, as noted under the Real Life listing, uses lots of these, but Corteo is actually about them; most of the major characters are turn-of-the-20th-century circus clowns. A stated goal of this show was to present funny and lovable clowns to audiences, especially children, who may never have seen them as such.
The LEGO Collectible Minifigs line includes a variety of clowns, all of them sincere performers of comedy. Even the Sad Clown.
Gauntlet: Dark Legacy has a Jester as one of the main classes. While a zany prankster who fights with slapstick, the Jester is portrayed as a well meaning hero who wants to undo the Big Bad's corruption of his realm into a Circus of Fear. One of the Jester titles is even Clown.
Dropsy has a particularly sad example. The main character, Dropsy the Clown, is bloated, ugly and monstrous-looking, having all the visual features necessary to be a Monster Clown. But he clearly suffers from some sort of mental disability, has an innocent and child-like demeanor, and is always trying his hardest to make people happy, even when everyone thinks he's a demented freak.
The fact that he tells horrible jokes doesn't help, although his determination to restore the circus, and teach Regina the truth about death, restores his worth in a lot of fans eyes.
The Sims: The clown who hassles your Sims is a nuisance, but he's not particularly evil. He's just bad at his job.
Hitman: Blood Money has a clown at a kid's birthday party whose clothes you can steal. The protagonist, 47, even once won a 'Clown of the Year' award. Of course, given the nature of the game, you may end up a Monster Clown instead.
Dark Cloud 2 goes both ways. While you do spend the early portions of the game fighting an evil clown and his circus troupe... you can also unlock a clown outfit for the male protagonist, build clown themed parts for his Ridepod, and be greeted by a perfectly friendly jester fond of hiding in dungeon treasure chests. He might even hook you up with above average loot!
Atop the Fourth Wall: Sick of the proliferation of Monster Clown characters, Linkara created Boffo the Clown to be a recurring character. Unfortunately for him, he was created at the beginning of The Entity's arc and as such promptly was kidnapped by The Entity. (He returned at the end of the arc). He's also Linkara's accountant!
The Powerpuff Girls has Rainbow the Clown, who is this except for the one time he was temporarily turned into an Enemy Mime. The girls still beat him up and toss him into jail after he turns back, but in a later episode he appears at the Powerpuff Girls' birthday party, so it seems he's back into freedom and as cheery as ever.
The Simpsons: Krusty is a cynical parody of this (more specifically, Bozo), yet despite his being greedy and disinterested, his merchandise being low-quality and dangerous and his show's shrinking budget, he manages to bring joy to children and we occasionally see hints that even after everything, he still loves comedy. Even if he is a hack.
Garfield and Friends: Binky the Clown is another parody. Unlike Krusty, he's passionate about being a clown. And although he's not monstrous or evil, he's incredibly obnoxious and irritating to just about everybody. Played far straighter in the comics, where Garfield genuinely enjoys Binky's antics. That is, when he isn't the target of Binky's antics.
Max Fleischer's Koko the Clown, one of the earliest cartoon characters.
Despite having been a Jerk Ass to everyone in the series (and even expressing unexplained hatred of clowns), Ed Bighead inadvertently discovers his passion for clowning around, and takes on a second job as a clown. He winds up being the most popular one in O-Town, even more so than his boss. Because he's afraid of what others will think, he tries to hide his second job as a clown in one of the most spectacular displays of Does This Remind You of Anything? on television.