I recently watched Butch Cassidy and the Sundance Kid again, and though the whole film is tremendous, I think that it is possibly the most iconic scene of the film that sums it all up so well. During the final moments of the film, Butch and Sundance are ambushed by the Bolivian police and half of the army, in a desperate attempt to capture the two "Banditos" who have robbed so many of the local banks (in stuttering Spanish).
After a dramatic shoot-out, and many Bolivian deaths (thanks to Sundance's marksmanship), the two affable outlaws are pinned down in a small room just off the main square of a village. After a short while the duo burst out, guns blazing, but against so many soldiers their fate is inevitable.
This final scene is excellent for several reasons. Of course it is a tremendous gun battle, very fluid and dynamic. Another reason the scene is so good, and encapsulates what is so great about the rest of the film, is the wonderful relationship and banter between the two protagonists. All the while that Butch and Sundance are slumped against the wall, injured, bleeding, and very likely about to meet their deaths; they don't mention this enormous elephant in the room. They talk about where they'll go next, Australia, and generally slag each other off for not being able to run or shoot. This typifies the quality of their relationship throughout the film, and also the quality of the script, which is as sharp as this all the time, and Paul Newman & Robert Redford are just fantastic too.
The final cool thing about the scene is how they achieved that final iconic shot, as I've explained before; it was shot, frozen at this point, imported into an empty photograph of the background before bleeding the colour out to make it match a lot of the other sepia photos within the film. This is just one of the reasons that Conrad Hall won the Academy Award for cinematography for his work on this film.
This is just one great scene out of so many in Butch and Sundance; definitely worth checking out if you haven't already; even if you don't like westerns, Newman and Redford make the story so enjoyable.