Kuragehime and Kaiji are underrated animes, it's probably cause they both don't have cute moe characters you get in anime these days.
Originally Posted by elvis8tweeter
The ...monogatari series are super underrated. I LOVE Bakemonogatari and Nisemonogatari.
As for manga: Zombiepowder!!! AMAZING series!
I have to disagree with this. The gatari series are very popular, there's a reason why it has multiple seasons and a movie. Well since it is from Shaft the ones also behind the whole Puella Magi another popular anime.