Aragorn started out as a relatively untrustworthy character in the Lord of the Rings movies, but he quickly established himself as the ultimate good guy. His quest to keep the Ring out of Sauron's hands was a testament to his strong character traits, as well as a few that caused him to second-guess himself throughout the story.
He was not a perfect man, but he was one with a conscience that guided his actions. Even at his lowest point, Aragorn continued to stand true to his convictions, and rely on the traits that had helped define his character over the years. It's what eventually led to him accepting his status as King of Gondor.
He Was Very Lowkey
For a man born from such a long line of Kings, Aragorn preferred to stay by himself most of the time. He'd trade and visit those closest to him, but for all intents and purposes, he was a very lowkey individual. During his days as a ranger, he kept a very low profile, primarily to keep Sauron's forces from discovering who he really was.
The only people he spent any prolific amount of time with during this period were the Rangers of the North, which were all lonely individuals to begin with. Their job was to wander the lands and hunt the forces of the Enemy, while living in relative solitude. Their deeds were never recorded, and they were viewed by normal folk as distrustful. Yet, this is the path Aragorn chose, which was in line with his personality traits.
He Lacked Self Confidence
Though he was one of the most courageous warriors of the Third Age, Aragorn lacked confidence in himself. Tolkien's novels made this clear, with Aragorn blaming himself for many of the tragedies that befell his friends during the course of the story. The Lord of the Rings novels contrast Aragorn with the films, where his self confidence is directly tied to the subplot involving his Kingly lineage.
This proved that Aragorn was not a perfect man, nor a superhero. Rather, he was simply a man who did what needed to be done, because it needed to be done. Nothing more, nothing less. However, he was extremely insecure about his bloodline, and the idea that he should claim the throne of Gondor. He believed it would have opened the door to another catastrophe, and for evil to rush in.
He Spoke In Quiet Tones
One of Aragorn's most popularized character traits in the Lord of the Rings films was his signature vocal delivery. Rarely did he yell, except in times of great frustration, or in battle. The rest of the time, he spoke in very soft, or lightly grumbling tones, almost with an aura of mystery attached to them.
This might have been done in order to show the maturity that hid behind such a young face. Fans of the LOTR movies know few facts about Aragorn, including his lineage as one of the Dúnadan, which meant he lived a much longer lifespan than that of a normal human. He'd seen a lot during his 80+ years up to the point of Sauron's return, and he may have mellowed early, at least in terms of his mentality.
He Was A Born Leader
He may have had the blood of Kings flowing through his veins, but Aragorn had no intention of ruling. Nevertheless, that bloodline did bestow him with a natural sense of leadership, and he came to be known as a very effective leader. In times of war, he led his men valiantly through conflicts, and during the time of the Fellowship, he had no trouble taking on the duty.
Aragorn was also a wise leader, particularly because he heeded the council of those in his stead. He weighed their advice against the facts on the ground, and reacted accordingly. When times got tough, he was forced to make the final call, knowing it could lead to tragedy. However, that's all part of actually being a leader, and Aragorn took it as such.
He Bore A Sadness
Aragorn's life was a difficult one, for he had several burdens to bear. First, he was burdened with the notion that he was the last of his bloodline, one soaked in shame due to the actions of his predecessor Isildur. Next, he had to contend with his relationship to Arwen, which he was never sure could actually work out, given their racial differences.
For this reason, he often felt like a stranger in the world that he wanted to protect, which became a burden unto itself. He couldn't fathom going home to Gondor to claim the throne, and he found himself struck with guilt over the idea that Arwen might give up her immortality to be with him, which ironically made them the perfect LOTR couple. This left him feeling quite sad, and alone, regardless of how many friends were at his side.
His Strength Of Will
While Aragorn had the same doubts and fears as any other person, he did possess a strength of will that was far beyond what most could conjure. No matter the situation, Aragorn never gave up, even when he believed that his actions might lead to a futile resolution.
He even faced down the spirit of Sauron himself, via the palantir stone, which would have driven a normal person quite mad with fear. Yet, he was able to hold his own against the machinations and manipulations of the dark lord, staying powerful and resolute the entire time.
He Was Compassionate
Aragorn might have come off as a rugged and stoic ranger who preferred to keep to himself, but his heart was large, and he wore it on his sleeve. He was never afraid to show compassion, as evidenced by all the nice things Aragorn did for others. This was best demonstrated in the way he protected the Hobbits, and viewed them as equals on their quest.
It was also this compassion that compelled him to follow Gandalf to Rohan, to free Théoden, and his people writ large. By the time the war had come to an end, Aragorn was finally prepared to rule as a compassionate King, after much practice as a regular man.
He Was Humble
Though he belonged to a very long line of Kings, Aragorn never let his bloodline taint who he was. He knew his strengths, but also acknowledged his weaknesses, and even when he was thrust into the duty of leading the charge, he never became boastful or arrogant.
Aragorn did know when to stand up for himself, but also when to stay silent, and listen to others. He could have easily thought himself too important to listen to the wizard Gandalf, yet he did, whenever possible. He valued the guidance of those who had a lot of experience, rather than think himself the only one who should have a say in matters.
He Was Charismatic
A man like Aragorn could never have led the Fellowship, or his friends in battle, had it not been for his inherent charisma. Though not a perfect man, Aragorn was nonetheless an ideal one, and a person that many could hope to aspire to be more like. He was able to inspire others, despite his humble demeanor.
Perhaps it was due to the balance he struck between being a warrior, and a peaceful man. Only when the situation called for it, did Aragorn engage in a fight, and only for the right reasons. The rest of the time, he inspired others with a strong sense of morality and ethics, making him a person people wanted to be around.
He Was Fearless
No feat was too frightening for Aragorn, and he refused to cave to fear, no matter what. He knew the value of retreating in the face of insurmountable odds, but it was not fear that drove him. Indeed, he had faced horrors that few warriors could even suffer in their worst nightmares, and charged forward when it was appropriate to do so.
He faced down the entire cursed Army of the Dead in one of Aragorn's most badass moments, and didn't flinch. He confronted Sauron with the palantir, and never broke a sweat. He faced down a horde of charging Uruk-hai, and grinned to himself, before taking them on. No man, army, beast or dark lord could ever break his courage.