Animeland

The country of Japan, but portrayed as a world that works like what Anime taught us.

In western works, it might serve as a parody of the anime fandom in general. In Japanese works, it might be a jab at Occidental Otaku who seem to actually believe in this, or lampshaded to emphasize that this particular work is more realistic than that.

The most common examples are:

Magical Girls in Sailor Fuku
Kaiju and Humongous Mecha stomping through the streets
Tokyo as the center of the universe
Salarymen
Tentacle Monsters
And various others...

Due to the Lowest Common Denominator, it might also include other Japanese pop cultural references, that are not really anime-specific, such as Ninjas, Kaiju or the Yakuza.

This is a part of the Hollywood Atlas, like Eagle Land, Eskimo Land, Yodel Land and the Land of Dragons. Thirty Seconds Over Tokyo is similar, but unfiltered (or at least less so) through the lens of anime.

Not be confused with the French magazine Animeland

Examples:

Advertising

Advertising of the Japanese made Uni-ball ball pens in the US invokes this trope by using a Humongous Mecha to promote their gel ink.

Anime & Manga

In Lucky Star, Occidental Otaku Patricia Martin has this worldview.
- In which the mangaka immediately lampshades as "the wrong idea on Japanese culture."
Arcade Gamer Fubuki portrays Japan as Animeland.

Film

In The Hangover, when a naked, angry Asian man jumps out of the trunk of the car, Alan tries to calm him down by saying that he hates Godzilla, too.
In Toxic Avenger, Toxie's father is Japanese. And a Corrupt Corporate Executive. And a sumo wrestler.
Teen Titans Trouble in Tokyo, See Below.
Robo Geisha: There is not a Japanese stereotype in existence that this movie does not portray. Yakuzas, Geishas, Ninjas, Samurai, Sailor Fuku, Kaiju, Tokusatsu... you name it.

Literature

The section on Japan in America the Book plays this for laughs.

Live Action TV

In Lexx's last season, a giant plant person invaded Japaneseland.
Animeland and the fan culture surrounding it were the object of satire in the SNL skit "J-pop America Fun Time Now!"
In Thirty Rock Tracy believes he is giving a speech over a live feed to a Japanese award show. He thanks all his Japanese fans, especially Godzilla. The he laughs and says he's just kidding...he knows Godzilla doesn't care what humans do.

Video Games

In Command and Conquer: Red Alert 3, the Empire of the Rising Sun faction's military units included psychic Magical Girls in Sailor Fuku, and Humongous Mecha. Their superweapon is a Psychic Explosion, and the engineer is a Salaryman. About the only thing missing are Naughty Tentacles. Oddly enough, The Soviets did have a giant squid in the previous game. (You can bet you'll find some fan-art of it if you look hard enough.)
- The Emperor's video briefings help tick any other boxes in the Big Book Of Japanese Clichés: his son wears a kind of samurai armour, he's seen practising sword forms, contemplating a bonsai tree, practising calligraphy, taking tea a lot, mentions a revival of Bushido, tells you to slice through the enemy "like the blade of a katana" and finally declares you "Supreme Shogun".
Destroy All Humans 2 parodies this. 'Takoshima' is filled with salary men, schoolgirls and at one point a kaiju is running around.
Osu Tatakae Ouendan and its sequel, especially since it was designed with a manga feel. There are two levels featuring schoolgirls, two with Kaiju fighting against a Salaryman or a Humongous Mecha depending on the game, and other Hot Blooded shenanigans. However, there are no tentacle creatures, (like that would really change anything), and a ninja only appears in the American localization.

Web Comics

Western Animation

Cow and Chicken: this Got Milk ad.
Kappa Mikey
The Simpsons episode "Thirty Minutes over Tokyo" has an announcement from the pilot as they're flying home:

"Uh, folks, we're experiencing some moderate Godzilla-related turbulence at this time, so I'm going to go ahead and ask you to put your seatbelts back on. When we get to 35,000 feet, he usually does let go, so from there on out, all we have to worry about is Mothra, and, uh, we do have reports he's tied up with Gamera and Rodan at the present time. Thank you very much."

Teen Titans Trouble in Tokyo is like this. It's definitely an Affectionate Parody, though, since the series is Animesque.
Phineas and Ferb's special "Summer Belongs To You" has this little sequence.
The season two finale of Dexters Laboratory starts off here with Dexter accidentally awakening a Kaiju, while trying to one-up two mecha pilots his age (who both look like Go Nagai characters). The rest of the episode has him and his entire family fighting said Kaiju back home, with the help of a Combining Mecha, under the guidance of a Kid Samurai.
Japan in Tokyo Mater, and as an extension, the Japan segment of Cars 2.