I love most of the ones already mentioned here.
Their was one quite a few years ago that I thought was terrific too, but I can't remember the name? It was about a blind cival war veteran that was a gun slinger of sorts. I always thought that movie was pretty daggone good!
As far as westerns go, I think when it comes to a gun fight, Clint Eastwood plays a gun fighter better than anybody else.
When it comes to just pure out guts, and principles, fights, and my favorite, the occasional open handed slap to some low life, John Wayne is positively "The Man" in my book. If every man in the USA was like the characters he played, this country would sure be a lot different!