Shigurui: Death Series is a great manga/ anime
Great story line and cinematic scenes I recommened everyone watch/read it.
Be warned though there is A LOT of blood, gore and nudity (also sexual content) so if your below 18,or really squeamish I don't recommend it.
Here is a link to the manga http://www.mangareader.net/1364/shigurui.html
I recommend reading it because it's further along than the manga and their are more details than in the manga (which is the case of with all books turned into movies, but believe me the anime still does it justice!!!)
Here's a link to the animehttp://www.animefreak.tv/watch/shigurui-online
One of the things I love about this series is that there is no clear cut good or bad guy, and there are parts where both main characters are good and bad, and you end up gaining sympathy for both!
Here is more info in general http://en.wikipedia.org/wiki/Shigurui
I really hope you enjoy as much as I do!