A shorthand reference of “that gay cowboy movie” is a cruel insult to the heavy-hearted power of director Ang Lee’s Brokeback Mountain.

Only part of the film’s ultimately somber overtones come from the secretive nature of a decades-spanning homosexual affair between two cowboys — conflicted, guarded Ennis Del Mar (a revelatory Heath Ledger) and outcast spark-plug Jack Twist (Jake Gyllenhaal).

The two meet while shepherding in a Wyoming mountain range in 1963. Larry McMurtry and Diana Ossana’s screenplay offers understated, understandable reasons why these two need each one another. It also creates uncomfortable bits when Ennis’ mental insistence that what he’s feeling is wrong and creates both knee-jerk bursts of fistfight attacks and affecting pleas for forgiveness.

Ennis and Jack’s passion persists through heterosexual marriages (Anne Hathaway and a career-best Michelle Williams), child-rearing and the looming threat of prejudicial violence.

Jack is the only one who dares grab with bare hands at the barbed wire twisted up inside Ennis. In one of 2005’s greatest performances, Ledger shows how Ennis’ slow-building appreciation and affection for Jack’s actions wear down his defenses.

Lee also is careful to show how each man deals with the children’s lives their affair throws asunder. Ennis and Jack are unable to fully embrace what their love means to them, but they use it to provide their kids and families with heartbreaking, emotionally honest advice.

Brokeback‘s most potent poignancy comes from universally relatable ideas such as a nagging love or dream that’s been lost, the tragedy of lives half lived and passions half fulfilled and, through Ennis, the gradual hope and comfort in knowing even incomplete joy is better than nothing at all.

Not just one of the greatest films of 2005, this is one of the greatest love stories of all time.