There are thousands of films about the 47 ronin!
Well, thousands not... but more than a dozen.
The first films about "Chushingura" were done in the silent era of cinema. The most famous of them was directed by Makino Shozo in 1928.
In 1932 Kinugasa Teinosuke directed one of the first talkie version, in 2 parts, starring Hasegawa Kazuo as Asano.
In 1934 Ito Daisuke and Itami Mansaku did their version, starring Okochi Denjiro as Oishi and Kataoka Chiezo as Asano.
In 1938 Makino Masahiro did his version too, starring Kataoka as Asano one more time and Bando Tsumasaburo as Oishi.
In 1941-42 Mizoguchi Kenji did the most "artsy" version, with Kawarazaki Chojuro as Oishi and Arashi Yoshisaburo as Asano. This version is available on the Net.
In 1954 Osone Tatsuo directed other version, "A Matter of Valor", starring Matsumoto Koshiro as Oishi and Takeda Kokichi as Asano.
In 1958-59 Watanabe Kunio directed the first version in color, starring Hasegawa as Oishi and Ichikawa Raizo as Asano. I think this version is also available.
In 1959 Matsuda Sadatsugu directed his version, entitled "The Great Avengers", starring Kataoka,but now as Oishi, and Nakamura Kinnosuke as Asano.
In 1962 Inagaki Hiroshi did his version, starring Matsumoto Koshiro as Oishi and Kayama Yuzo as Asano.
In 1994 Fukasaku Kinji did a very strange version, entitled "Crest of Betrayal", starring Sanada (The Last
Samurai) Hiroyuki as Asano. This version is also available on the Net but I warn you: IS NOT VERY LOYAL with the story.
I think there are a lot more, and several TV series too.