Anime that you feel gets less attention than it should.

Flying Witch also higurashi especially the visual novel. Since most people start with the anime.

Sasami magical girls club is a good one. Mostly for more slightly younger people but its is just so cute and some stories just Whams you with the feels train.

I think Mononoke (not the movie), Scrapped Princess, K, and Tears to Tiara were all good but I almost never hear anything about them.

Jormungand! It's one of my favorites from the same studio as Black Lagoon. Koko and Jonah together make for an awesome ride.

For me it's an anime called Karas (or Karasu in Japanese). It's a great action movie but whenever I talk with other Otaku it seems like no one has ever heard of it.