Animator vs. Animation has a decently-sized international audience, due to the lack of any sort of dialogue bypassing language barriers. This was more or less exploited by the creator, Alan, as he wanted people around the world to enjoy the series without being forced to know English. There are episodes which feature text dialogue, but this isn't used often and is often limited to one or two scenes when it does get used.
Animutation is actually pretty popular in Japan. Sometimes Japanese netizens would make misleading links to animutations such as Suzukisan and Hyakugojyuuichi in a similar fashion to Rickrolling. In Japan, Hyakkugojyuuichi is considered a classic flash animation much like it is in the west, perhaps even more remembered.
The British asdfmovie videos are enormously popular in the United States, thanks to the Rapid-Fire Comedy and Black Comedy being liked by both countries.
Taiwanese Edutainment show BabyBus is well-known in Taiwan, but it's huge in Japan. Physical media releases of the show, as well as merchandise such as stuffed animals, exist in the country, the videos often appear on YouTube as recommended to those of popular Japanese children's franchises, and it appears in the magazine Baby Book alongside Anpanman and Inai Inai Baa!.
It is also very popular in Latin America, that fans have not only made a fandub of the pilot, they have also made severalcovers of Addict and even rap battles between Charlie and Blitzo.
hololive grew for itself an unusually large fanbase outside Japan compared to other V-tuber groups thanks to clips of several members' streams being translated by fans into English, Indonesian and other languages which subsequently went viral and led to the establishment of overseas branches for those languages. Within the group, several individual members are also noted to have specific foreign fanbases:
Aki Rosenthal, ever since an clipper who made her (and her low follower count woes at the time) known to the West, she experienced a sharp increase in western fans, many from Reddit. The reasons vary, but it's often a mix of her dancing, music, and how her streams tend to be cozy. Aki has responded to this with learning/using more English in her descriptions and being one of the very first to join Reddit. She also has personally posted comments in vids which have promoted her. These days you can find her stream chats to be often filled with English speakers.
Korone Inugami has a very sizable Western audience for a combination of reasons. Her enjoyment of Western media, the dissonance between her cute voice and image and her love of horror and horrific things, willingness to engage with Western fans and learn English, and her willingness to try all sorts of different Western game suggestions have quickly endeared her to non-Japanese audiences. Even amongst Spanish-speakers, where virtual idols are just starting to become an extremely niche interest, Korone is noticeably more popular than the rest, thanks in part to clips of her speaking a few simple Spanish sentences.
Towa Tokoyami gained a lot of attention from the Western fanbase due to an incident in one of her Apex streams that garnered backlash from some Japanese fansbut brought sympathy from English speaking viewers, bringing attention to her more cute behavior and Adorkable moments. It's quite telling that on nearly all of her streams, most of the comments are in English. In fact, overseas fans went from making up almost half of her superchats (revenue and number of) for the month of July 2020 to reaching 65% of her superchat income and forming 52% of her total superchats the very next month after her 3D debut and birthday celebration. This sizable overseas fanbase has also been noticed by her colleagues, who sometimes comment on her unusually large foreign fanbase.
Shishiro Botan is incredibly popular with Russian-speaking viewers, due to her love of First-Person Shooter games and her striped design being evocative of Adidas, which is iconic in Russia. As of 5th Gen's debut, no other member in hololive has such a noticeable Russian-speaking fanbase compared to her, to the point where she is the only one to have a Russian version of the standard streamer rules in her video descriptions.
The Holostars branch are more recognizable overseas than its home country, judging by the English comments.
After being featured on an investigative report on a Korean public broadcast, Amelia (and Gura, who wasn't featured) has gotten a lot more Korean viewers and Korean translation clips.
Kronii is also well-liked in Korea, since she's one of the only V Tubers fluent in Korean.
Properly speaking, Ollie Kureiji is part of the Indonesian branch. However, since she's fluent in English and Japanese as well as Indonesian (and also both multi-talented and a Genki Girl of egregious proportions), she has something of an inter-branch appeal, and it's not uncommon to see her rapidly flipping between the three languages to respond to chat.
Metal Family is very popular in Latin America, including Brazil. Even its creator, Russian woman named Alina Kovaleva was surprised by this fact. Many comments come on Spanish and Portuguese.
ENA is quite popular among Japanese fans, likely due to its quirky and surreal nature. It's popular enough among them to the point where an unofficial Japanese dub was made, which gained the approval of Joel himself.
RWBY was initially popular in Japan, with a dub that included veteran voice actors like Megumi Hayashibara and a manga adaptation. Volumes 4 and 5 reportedly had an entirely different reception with Japanese fansnote Those seasons are still a bit of a Broken Base among Western fans, but Japan's reception of them was flat-out negative, though with later volumes it appears to have picked back up (also partly driven by there being licensing issues that prevented it from getting new dubs), to the point of having an actual anime series produced.
In-Universe Examples
Strong Bad Email: According to Strong Bad, the "Geddup Noise", AKA the sound of Strong Bad getting out of his chair, became really popular overseas to the point that it became a cultural phenomenon and eventually left the show. It currently lives in a house in the Coches mountains, but it still shows up for the occasional celebrity endorsement. Keep in mind this is a sound effect we're talking about.
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