What about making a separate thread with the anime entries ?
The list will be a neverending growing one, if you are slowly adding up most of the TV series/OAV/Movies that never saw a proper release on the western countries (at least english speaking ones). And their number can be counted with 3 digits at least. To give you a clue, I have a list of all anime ever released & known to me, and the total is over 4000 entries (including all the ones officially released outside Japan, having fansubs, etc). The OAV part alone is around 1000 !
Most of the recent additions have nothing to do with "hentai", it's not because you can see breasts and nudity that it's restricted-to-adult material. Even the most mainstream TV series have their random ecchi moments. I feel like this thread is completely shifting from its original goal.
Making a "rare anime hunting list" is not bad in itself, but don't mix tissues and towels as we say here :happy:.
I have some information about the new titles, I'll try to compile that after a night break ...