This does not necessarily qualify as the best gunfight by any means but it sure was offbeat. It was a relatively recent movie that started out like a regular Western but turned into some kind of monster sci-fi movie. But the part at the beginning was good.
It started with a stagecoach arriving in town just before a hanging was about to take place. Just before the hanging was about to happen, a woman using a bolt action rifle, if memory serves, up in a bell tower starts shooting and the condemmed man makes his escape, rather like Hang 'em High. Then everyone runs off into the desert and things happen. But the opening was really interesting. Don't know what else happened.
So what was the movie?
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.