What prompted Ennis's father to show him the dead gay man? Did he suspect that his son wasn't straight and was trying to scare him? Or was there no prompting and he just wanted to instill his prejudices into his son at an impressionable age?
Is Loreen telling the truth about Jack's death? Does she genuinely believe that her husband's death was because of an accident or does she know all along about Jack's homosexual side and that the death was caused by hate-crime? The fact that Anne Hathaway claims that she herself didn't know, they recorded the scene twice with two motivations in mind, and they mashed together the result as the final cut doesn't help.
Award Snub: Movie critics generally see the decision to award Crash with Best Picture over Brokeback as one of the biggest Oscar mistakes of the decade, if not all time. It's become an even greater consensus in the years since, as Crash has not aged well compared to that year's other Best Picture contenders. The voters are commonly accused of wimping out by awarding a movie with the relatively safe message of "racism is bad."
Awesome Music: The music from the trailer ("The Wings") is very touching, and it became a staple of slashyFan Vids. But it's very cool on its own merits.
Fridge Brilliance: When Ennis finds his and Jack's shirts hanging in their childhood closet, Ennis's is tucked inside Jack's. By Heath Ledger's idea, they are reversed when Ennis takes them home after Jack's death. The shirts can also be interpreted as each other's heart. Jack putting Ennis's jacket inside his indicates that Ennis has always been inside Jack's heart. Ennis putting Jack's shirt inside his symbolizes that Jack will always be in Ennis's heart.
The second night in the tent; Not only is it the first tender, romantic scene in the film, it also seems to be the first time that Ennis ever experienced any kind of physical love and/or affection from anybody. Plus the fact that Jack is gentle and patient with him in spite of his nervousness of being with another man.
While it is unknown whether or not Jack's mother knew her son was gay, unlike her husband, she is kind and hospitable towards Ennis when he arrives (offering him coffee and cherry cake), allows him to keep the shirts from Jack's closet (which Jack kept all those years since their first time on the mountain), and even invites him to return if he wishes to.
The fact that Ennis decides to call off work for his daughter's wedding, and gives his daughter and her fiancee his blessing; "To Alma and Kurt!"
Part of the reason for all the jokes about the premise (and the subsequent misinformation about the men's jobs) was a South Park gag from years before Brokeback Mountain was made about all independent movies being about "gay cowboys eating pudding"; there may not be any pudding, but otherwise... In fact, Trey Parker and Matt Stone commented in an interview:
Stone: If they have pudding in that movie, I’m going to lose my mind.
Parker: No, if there’s pudding eating in there, we’re going to sue.
Internet Backdraft: At the time, whether this movie should have won over Crash was quite the debate-starter (to say nothing of those who think neither deserved to win). Now, while it's still not consensus that Brokeback was the best film that year, most film critics agree that Crash should not have beaten it.
Some were rather upset about the movie centering on a gay couple.
Jerkass Woobie: Jack and Ennis unapologetically cheat on their respective wives and had an affair with each other, constantly lying for 5 years for Ennis or more for Jack. Despite, or maybe because of this, they are miserable in decades ever since they met in Brokeback Mountain, unable to have fulfilling and steady lives with both each other and their own respective private lives. Even factoring the cheating nature of it, nobody deserves the suffering.
Ennis, instilled by his father that homosexuality is bad by having to see a gruesome corpse of suspected homosexual tortured by townsfolk at the age of nine, is torn between his feelings toward Jack, his family life (especially his daughter), and social stigma of two men living together. As a result, everything in his life falls apart; He and his wife had a divorce, he was unable to find another love even though there's another woman falling for him, he financially struggled all by himself due to child support obligation to the point he has to live in a small trailer with few furnitures by the end of the movie, and he had no chance to further his relationship with Jack aside from occasional "fishing trips," breaking his heart time and time again, because he was afraid of people's persecution. Worse, he learned how deep and serious Jack's feeling had been toward him right after he found out Jack had died, denying him of a chance for another happiness in life.
Jack obviously had a strong feeling for Ennis and was serious about forming a relationship with him, once planning on building a cabin together in his family's ranch house for them to live together and help "lick the ranch into shape." However, Ennis couldn't reciprocate because of his own problems above leaving him anguished for a very long time, unable to move on for 20 years. Despite having better financial condition, he is trapped in an unhappy marriage where Lureen seemingly care much more about work than family and his father-in-law obviously doesn't like him. In particular, after hearing Ennis had a divorce with his wife, Jack immediately drove to where Ennis was, thinking that things between him and Ennis could finally change and Ennis had finally decided to live with him only to go back in tears after another rejection. When it looked like he was able to move on from his love to Ennis as indicated by his father saying he invited another man to build the ranch and planned to leave Lureen, he had to die before he was able to find happiness in what implied to be a hate-crime disguised as accident.
The speech leading up to "I wish I knew how to quit you". Despite going memetic, the line in context was very emotional.
They Wasted a Perfectly Good Character: Lureen Newman, who did nothing of importance in the final third of the movie. She didn't even react to the confrontation between Jack and her father! This is even more notable in the story in which she only appeared in one scene (to tell Ennis about Jack's death).
What an Idiot!: Ennis and Jack go on infrequent fishing trips while actually they are basically cheating on their wives. They have been doing this for five years. You'd Expect: They bring home fishes, or at least touch the fishing equipment to keep up with the lie, especially knowing that Ennis's wife and kids love fishes. Instead: They didn't try to fish anything while saying they caught a lot of fish without bringing one home. Worse, Ennis didn't even open his creel case once as later noted by Alma when she said the note she put inside was still there. Granted she already knew her husband was cheating but at least Ennis could try.
The Woobie: Alma, who only wishes for a happy family, witnesses his husband passionately kissing another man. Let alone the homosexual nature of the relationship, she sees his husband cheating while they had been financially struggling with two kids to raise. She was aware that the fishing trips were all just a facade and she could pick the sign that her husband's love gradually diminished. She is still emotionally scarred from the experience even after divorce, as seen during thanksgiving scene