"Blind Fury" starring Rutger Hauer has some great footage. It's actually based on one of the Zatoichi movies, which are also a lot of fun. Totally unrealistic! But a lot of fun to watch.
Highlander, of course.
The Duelists, same two guys go at each other every couple of years, but each time with a different style sword. One time it's rapiers, one time small swords, etc.
LadyHawke, another film starring Rutger Hauer, the duel at the end is especially good.
Red Sun, staring Charles Bronsen and Toshiro Mifune, actually doesn't have a lot of sword fights, but you get to see Mr. Mifune use his sword in some very basic creative ways. It's kind of cool to know that someone was creative enough to use a katana in a film to do something else besides kill people.
Seven Samurai: Excellent film, with some amazing sword fights. Especially those involving Kyuzo (I believe that's his name) the one involved in the duel.
MMMMMmmmmmm I'll think of some more.......