Now and Then, Here and There, a very heavy anime, I guess it’s heaviness is the reason why it never became super popular, but still, I think it still had what it takes to become an anime of cult.

Shiki, also deserves more recognition than what it has.

Kemono no Souja Erin, I didn’t finish this one, but the first half is amazing, unless the second half looses quality this one should have been popular too.

Also, it’s worth to mention Gunslinger Girl.

All these shows are kinda dark, so maybe that’s why they never got the recognition they deserve.