One particular favorite? Hmm that is tough for me because I have so MANY.
Think I ll give it to Yojimbo, with Seven Samurai a close second. But man, there are tons more -
Chushingura
Throne of Blood
Sanjuro
Harakiri
The Samurai trilogy
The Doom Sword
Samurai Assassin
Zatoichi
Check out most of Toshiro Mifune films.
The one which you will have a lot of fun watching is Red Sun, in which Mifune combines with Charles Bronson to pursuit Alain Delon! Add to the mix, the lovely and alluring Ursula Andress!
I haven't seen many modern Samurai films except Zatoichi so can't comment on them. Most of my fave films belong to the 60s-70s period.