Incredibly Conspicuous Drag

"How it becomes clear that he is not a woman is not nearly as interesting as how anyone could possibly have thought he was a woman in the first place. He plays a woman as if determined, in every scene, to signal to the audience that he's absolutely straight and only kidding."

—Roger Ebert on Matt LeBlanc in All the Queen's Men

Somebody passing for the other gender is a common trope in comedy, all the way back to Shakespeare. However, it usually works only if the actor in question actually makes an effort to look and behave like a member of the opposite sex, otherwise the audience's Willing Suspension of Disbelief is broken and instead of being about, say, a man trying to pass as a woman, the work becomes about how a group of morons didn't realize they were trying to pick up a drag queen. Occasionally it works, if applied side by side with Rule of Funny.

Compare Paper-Thin Disguise. A Sister Trope to Larynx Dissonance and (naturally) Disguised in Drag.

Examples of Incredibly Conspicuous Drag include:

Anime and Manga

Magical Shopping Arcade Abenobashi‍'‍s Crossdresser "Ms." Aki is never outed, but is rather obvious—so much so that it seems the rest of the cast is aware of it and just treats him/her as a lovable eccentric.
All the crossdressers from One Piece are incredibly ugly and clearly don't shave, though they still behave much like women. The only exception so far is the secondary character Izou: The only thing that gives away his sex is his lack of a cleavage.
In Penguin Revolution, the talents and managers of Peacock are required to dress in drag for a publicity event. Most of the actors pull it off remarkably well, but Kaneda, one of the managers, just looks like a man in a dress.
Mad Bull 34 takes the cake, here. The "Mad Bull" himself, an eight-foot-tall muscular behemoth of a police officer with a full beard and mustache, goes undercover as a nun and as a female prostitute. He somehow expects this disguise to work.

Comic Books

The Beagle Boys in Donald Duck comics. They still wear their masks, and don't shave.
Aversion in a Don Martin cartoon for Mad Magazine: Men looking for an escaped convict at a train station see a hairy-armed, tattooed, stubble-faced person in a dress walk by. One of them pulls off the person's wig and they jump on the presumed escaped convict... but let her go with shamefaced apologies.

Film

As the page quote indicates, the WWII comedy All the Queen's Men (allegedly Based on a True Story) completely destroys any possibility of seeming authentic because the actors (including Eddie Izzard) make absolutely no attempt to be believable as women.
A number of the Carry On films involve Sid James or Bernard Bresslaw (or another similarly unmistakeably masculine cast member) wearing a dress, and the authority figure they're trying to evade falling instantly for him, despite the fact that he's clearly Sid James or Bernard Bresslaw wearing a dress. (The fact that the authority figure was frequently Kenneth Williams may add a bit of subtext to this.)
Played for Laughs in Gangs of New York when an incredibly obvious transvestite (stubble and all) shows up to a dance where males are paired with females. He, of course, goes to the "female" side.
Subverted in The Rocky Horror Picture Show. Frank N. Furter doesn't really try to pass off as a woman yet Brad (ASSHOLE!) ends up falling for his seductive charm anyway.
Averted in Some Like It Hot. Jack Lemmon and Tony Curtis actually walked around the studio lot in drag in order to make sure they could realistically pass for female. The scene were they try using mirrors in the public ladies' room in order to fix their makeup is based on something they actually did while on the lot.
- When asked why his "Josephine" was so much more feminine than Jack Lemmon's "Daphne", Tony Curtis explained that he was so scared to be playing a woman (or a man pretending to be one) that his tightly wound body language could be read as demure and shy, traditionally feminine traits, whereas Lemmon, who was completely unbothered, and "ran out of his dressing room screaming like the Queen of the May," kept much more of his masculine body language.
Sorority Boys is a textbook example. Back to Roger Ebert:

"What is unusual about "Sorority Boys" is how it caves in to the homophobia of the audience by not even trying to make its cross-dressing heroes look like halfway, even one-tenth-of-the-way, plausible girls. They look like college boys wearing cheap wigs and dresses they bought at Goodwill. They usually need a shave. One keeps his retro forward-thrusting sideburns and just combs a couple of locks of his wig forward to "cover" them. They look as feminine as the sailors wearing coconut brassieres in South Pacific."

In Taking Woodstock, Liev Schrieber plays Vetty von Vilma, a transvestite woman. In the part he's very muscular and has an apparent deep voice, in addition to very visible facial hair.
There was a Three Stooges short where Curly dressed like an Indian maiden and a mountain man fell in love with him. Guess it's been a really long time since he last saw a woman.
Averted by Dustin Hoffman in Tootsie. He might not be an attractive woman (a fact lampshaded several times in the film) but he at least looks like one. That Oscar nomination was well-deserved.
The failure of White Chicks is generally considered to be a combination of this and disturbingly unconvincing makeup.
In Gentlemen of Fortune, the crooks end up escaping in drag. Not only it's incredibly conspicuous, one of the crooks still tries to hit after girls and tries to use the men's bathroom.

Literature

Averted/Lampshaded in The Adventures of Huckleberry Finn, Huck goes into town disguised as a girl, but a woman he encounters immediately tells he's just a boy in disguise.
Hilariously played with in the Discworld novel Monstrous Regiment. Blouse takes the guise of a woman and is ridiculously bad at it, to the point where all the washerwomen notice right away but don't say anything because they think it's entertaining. But while the women aren't fooled by his awful, extremely stereotypical act, the male guards buy it completely. The funniest part is when the female soldiers masquerading as male soldiers decide to don women's clothing to also infiltrate enemy lines, they're immediately accused of being this trope, saying that they're obviously male and it's the worst attempt at drag they've ever seen.
Dave Barry's Only Travel Guide You Will Ever Need recommends that airline passengers who might fit the profile of a terrorist ("Sex: Male; Age: 15 to 74; Looks Suspicious: Yes") to draw away the attention of security personnel away by wearing a dress and "periodically remarking out loud to nobody in particular: 'I certainly have a lot of body hair, for a woman!'"

Live-Action TV

Bosom Buddies ran on this trope.
Done on purpose in the short-lived series The Ugliest Girl in Town.

Oral Tradition, Folklore, Myths and Legends

There is a Norse story in which Thor must disguise himself as Freya in order to trick the giants. The giants fall for every one of Loki's excuses about why "Freya" looks so haggard and has such a big appetite and can drink so much.

Theatre

The character The Old Snatch in the musical Me and My Dick—there are other cross-dressing roles, but this one is played by a man with a gravelly voice and a beard.
The original stage version of Hairspray cast gravelly-voiced Harvey Fierstein as the mother, Edna Turnblad. The original movie and movie-musical also have the role played by a man, but they attempt to make the mother somewhat feminine and are not examples.
The traditional kickline in every original annual production of the Princeton Triangle Club is performed by eight to twelve of the club's burliest male members insufficiently disguised (deliberately) as women.

Video Games

In SNK Gals Fighters, Iori Yagami disguises himself as "Miss X" by wearing a Sailor Fuku and a mask and insisting he's a girl. Nobody who sees him believes it.

Web Comics

Happens in The Noob, when Your Name Here, a large man with the Face of a Thug, dresses up in drag for a story arc.

Western Animation

In an episode of Bob's Burgers, Bob makes friends with some fairly successful transvestite hookers, who look exactly like men in spandex dresses.