Hello!
Seems like everyone is boosting about those old kurosawa movies... Those are good indeed but there are lots more to watch.
The best ones are:
Mibu Gishi Den (when the last sword is drawn, this is just so great)
Tasogare Seibei (twilight samurai, about a poor samurai whos forced to sell his katana to feed his children...)
Makai Tensho (Samurai reincarnation, the remake, great movie with characters like Musashi Miyamoto and Yagyu Jubei!)
Shoguns Samurai (Maybe the best? Starring Sonny Chiba...)
There are lots more like the Itto Ogami movies (Lone Wolf, the reason why suio ryu is practiced in north america? , Musashi-trilogy and so on, those I mentioned are made in last two years (except shoguns samurai, but thats just killer) and are definitely worth watching.
Feel free to ask, I collect Samurai movies and must have more than hundred or so?!