This two-part mockumentary
about rabid fans (Otaku
)and particularly SF/Anime fans in Japan by Gainax
is absolutely priceless. The title is literally Fan's Video.
This tells the story of some High School dropout friends who are all Otaku who use their hobbies to start businesses and built an empire of Otaku. The main character wishes to become OtaKing. This is I believe a somewhat fictionalised (and at the end 'extrapolated') history of Gainax itself.
Interspersed through the animated story are interviews with Otaku of various types (mostly I believe played by Gainax staff) and the results of polls and surveys about Otaku. These are not just anime or manga fans either but a large cross-section including gun and costume-play as well.
There are a lot of in jokes and little visual treasures to notice (one of the places where AnimEigo's comprehensive liner notes are a godsend). Some of them are extremely obscure and no-one can be sure that they have found all of them. There are posters, haircuts, hardware, catchphrases, etc. all over the place.
All the sections start with the date of an event working their way up through history. The last two are the Moon breaking orbit on 13th September 1999 (as in Space 1999), and the launch of the Eltrium, one of the very big ships from GunBuster.
This is one of my favourite anime (though I have only ever seen the Animeigo subtitled version). The number of times I was watching it and suddenly realised the parallels between myself and one of the interviewees was frightening.