For a 50 year old flick, it certainly holds up very well.
And it covers so many universal themes: honor, pride, prejudice, selfishness, greed, righteousness, compassion, and respect just to name a few off the top.
And it has influenced so many other movies, most notable The Magnificent Seven, which, from what I understand, is just a western-themed remake of Seven Samurai.
The first scene with the mounted bandits riding over the mountain, I recognize from Ninja Scroll.
The character of Kyuro, I feel, was the inspiration for Street Fighter's Ryu, with his only desire of perfecting his art.
And when was High Noon made? It seems to the be the polar opposite and antithesis (in regards to the main scenario) to Seven Samurai, but I'm not sure if it was made prior to or after Seven Samurai.