So I guess you want to get more mature recommendations?

To your eternity - very beautiful, but not finished yet

Ghost in the Shell - a must watch

Samurai Champloo - very fun

Texhnolyze - just watch 1 or 2 eps to see if it is for you

Serial experiments Lain - not about adults but confusing and more Seinen I’d say

Hellsing Ultimate - gory vampire hunter series that also is a bit silly

And of course the Ghibli movies are highly recommended