I, too, became interested in Japanese "Samurai" films from reading Usagi Yojimbo. There are sooo many good ones out there, it is hard to narrow down a list of recommendations.
Yoji Yamada's trilogy of films are probably among the best original films made in the genre in the last 10 or so years. Miike, director of the recent 13 assassins, is just one of a long line of directors remaking older films.
I have to claim preferrence for the "classical" era of films from the 1950's (including Kurasawa's Seven Samurai and Inagaki's Musashi trilogy), and the "New Wave" era which started in the 1960's with films like Kurasawa's Yojjimbo, Gosha's Three Outlaw Samurai, Okamoto's Sword of Doom, and Kobayashi's Seppaku (Harakiri), as well as film series featuring characters like Zatoichi and Nemuri Kyoshiro.
(The Rebel Samurai DVD set features some great films from this era)
While there were still a lot of good "Samurai" films made in the 1970's, they were startingto lose a battle with all the new "samurai" television programs and had to start offering material which could not be shown on TV, mainly more violence and nudity. The Lone Wolf and Cub series of films, mainly directed by Misumi, are the best known from this era of "exploitation" films.
Speaking of the Samurai" television series, there were quite a few good ones produced, including a Zatoichi series which featured Shintaro Katsu (star of the Zatoichi film series), a Lone Wolf and Cub series (actually better than the film series and which followed the manga stories pretty closely), and a series called "The Mute Samura" which starred Wakayama Tomisaburo (star of the Lone Wolf and Cub film series) as a samurai on a mission of vengence.
Television also produced some of the longest lasting series around, series like MITO KOMON (1969) - 1152 episodes and ABARENBO SHOGUN (1975) - 832 episodes, both series which spanned decades.
A great web-site about Samurai Films is
The Jidai_Geki Knights
