People playing themselves
Anime
Characters, eponomous namings or cameos portrayed by their real life counterparts (virtual & off-topic cases are included for now)
Thanks to helpers (you know who you are :3)
*Sorted by member count. Off-topic at the bottom
Thanks to helpers (you know who you are :3)
*Sorted by member count. Off-topic at the bottom

TV, 1996,
? eps
Me:-
Author:-
Minami Takayama (VA of Conan & TWO-MIX vocalist) as singer Minami Takayama
Singer Mai Kuraki as Mai Kuraki
Singer Mai Kuraki as Mai Kuraki

TV, 2013,
12 eps
Me:-
Author:5
Ep5 21:00 - Sphere (left to right: Tomatsu Haruka, Kotobuki Minako, Takagaki Ayahi, Toyosaki Aki) appear onstage to perform the OP

TV, 1999,
26 eps
Me:-
Author:-
Director Shinichi Watanabe as Nabeshin (Also cameos as himself in numerous other series)

TV, 2024,
12 eps
Me:-
Author:7
VTuber Tokoyami Towa as herself - Ep1 11:50, Ep2 21:47
+ several other Hololive members
+ several other Hololive members

TV, 2020,
12 eps
Me:-
Author:-
Mafia Kajita as Gurasan (a character who appears to be designed off himself)

Movie, 2002,
1 ep
Me:-
Author:-
Mangaka Eiichiro Oda as announcer Odacchi

TV, 2022,
11 eps
Me:-
Author:-
Ep1 & 12 - Shouta Aoi as Shouta Aoi faces an epic encounter against T.M.Revolution in a live action Kamen Rider parody

TV, 2023,
12 eps
Me:-
Author:-
Pro-golfer Momoko Oosato as Momoko Oosato

TV, 2020,
25 eps
Me:-
Author:-
Ep1 7:40 - The Osomatsus meet their voice actors (Jun Fukuyama, Hiroshi Kamiya, Yuuichi Nakamura, Daisuke Ono, Takahiro Sakurai) at their graduation ceremony

TV, 2016,
50 eps
Me:-
Author:-
EP38 - Former AKB48 member Mayu Watanabe, as undercover idol/witch Mayu Watanabe, hosts the Pumpkin Bird Festival

OVA, 1996,
2 eps
Me:-
Author:-
VA Mitsuko Horie as Tsumiko Horie, a character named after her
Thanks to @ooReiko
Thanks to @ooReiko

OVA, 2013,
1 ep
Me:-
Author:6
7:50 - Characters meet their VAs

TV, 2008,
60 eps
Me:-
Author:-
Enka singer Sachiko Kobayashi as herself ep 28
Thanks to @ooReiko
Thanks to @ooReiko

Special, 2018,
2 eps
Me:-
Author:-
Vtuber Kizuna Ai as Kizuna Ai narrates the segment

TV, 2004,
52 eps
Me:-
Author:-
Mangaka Yutaka Hara cameos in every episode (mostly in image only, occasionally with commentary)

OVA, 1996,
2 eps
Me:-
Author:7
VA Hekiru Shiina as lovestruck supervillain Hekirunrun Shiina

OVA, 1992,
1 ep
Me:-
Author:4
Seikima-II band leader Demon Kogure as Demon Kogure

TV, 2022,
12 eps
Me:-
Author:-
-- Off-topic but notable examples below --
Miku's voice provider Saki Fujita as Miku Hatsune
Miku's voice provider Saki Fujita as Miku Hatsune

TV, 1989,
51 eps
Me:-
Author:7
Anime based off Eriko Tamura who provides Eriko Tamura's singing roles (talking is voiced by a separate VA)

Movie, 1991,
1 ep
Me:-
Author:-
Anime based off rock band ZIGGY & featuring their songs (band members are voiced by separate VAs)

OVA, 1989,
4 eps
Me:-
Author:4
Mangaka Wayu Suzumiya as herself in the post-anime talk segment (Also kind of cheating but worth mentioning since the mangaka directs, voices and sings in their own adaptation)

TV, 1993,
? eps
Me:-
Author:-
Also off-theme but worth mentioning...
Features a chara, Makaino Kouji, designed off the composer of the same name who has written many theme songs for the series (though different VA)
Features a chara, Makaino Kouji, designed off the composer of the same name who has written many theme songs for the series (though different VA)