Although there are some exceptional Westerns (such as The Oxbow Incident, The Gunfighter and The Fastest Gun Alive), this is my favorite.
I must first point out that Westerns are NOT among my favorite movies. I like them in small doses or when they rise above the crowd.
This movie is GREAT in so many ways. First, the soundtrack is tops. It's magnificent in scope and fits the movie so well. Second, the acting is great. Particular standouts are Gregory Peck (as the strong, confident yet humble newcomer), Charlton Heston, Charles Bickford and Burl Ives. Overall, this movie seemed to best showcase Ives and Peck, as their characters were so solidly written and mesmerizing. Third, as alluded to in the last sentence, the writing was incredible and it was in many ways an "anti-Western" that deliberately avoided clichés and debunked some of the macho excessiveness of some Westerns. Fourth, the brilliantly paced and masterful direction of William Wyler (perhaps the greatest Director who ever lived).
This is the plot in a nutshell: Gregory Peck is an Easterner who had been a ship's captain who met a girl (Carol Baker) and agreed to marry her and move back west with her. It turns out her father (Bickford) owns most of the county and is way too adamant on proving his machismo--particularly when it came to altercations with another big-shot landowner (Ives) who is his rival. The problems all begin when Ives' son (Chuck Conners) and his buddies give Peck a nasty hazing. Peck laughs it off but Bickford is bound and determined to "teach that trashy clan a lesson".
It becomes painfully obvious through the course of the movie that BOTH patriarchs are pig-headed bullies who won't back down until their rival is pushing up daisies! Peck realizes this rather quickly but is disheartened that his fiancée is all for a countrywide bloodbath. Her lust for revenge and mayhem drives poor Gregory Peck away--into the arms of the luscious schoolmarm (Jean Simmons--not THE Gene Simmons from KISS, but the actress).
As a compromise, Peck offers to buy a piece of land under dispute by the two patriarchs and give them BOTH equal access to the land. Neither one really wants this solution, as it will preclude them from killing each other.
I won't tell more about the basic plot or the conclusion, as it would spoil the experience, though there are a few WONDERFUL moments I want to highlight.
First, the cowboys try to get Peck on an evil (and seemingly unbreakable) horse, but he declines. They think he's "yellow" but he just doesn't think he has to prove himself to others. Instead, when no one other than Raoul (the servant--who is exceptionally well-played), he tries again and again to ride the horse until he ultimately succeeds into saddle-breaking it.
Second, for much of the movie, Charlton Heston (Bickford's foreman) is itching for a fight with Peck. Again and again, Peck backs off--not because of perceived cowardice but because he has neither an argument with him nor did he feel I needed to fight. Now remember, Peck was introduced as an ex-sea captain--this was certainly NOT a wimpy profession, but he was so self-confident in his own masculinity that he just felt no need to prove anything to himself or his fiancée. Finally, after repeated provocations, Peck agrees to fight but not publicly. Instead, they fight all alone in an open field. The fight lasts for what seems like hours, as they exchange blow after blow. All this is shown NOT with the typical closeup, but with a DISTANT shot in order to avoid glamorized the fight. Finally, after they both are spent, Peck asks Heston if this REALLY accomplished ANYTHING! This was a beautiful moment.
Overall, I think this movie's theme is REAL masculinity versus FAKE put-on masculinity and it does a masterful job.