Which anime are, to you, underrated classics?

Shows that are definitely considered "classics" but not as widely known or talked about as the more popular classics like Death Note or Bleach.

Off the top of my head:

Texhnolyze

Natsume's Book of Friends

KareKano (His and Her Circumstance)

Wolf's Rain

Ergo Proxy

And many more 90s/2000s anime