Viggo Mortensen did not receive an Oscar nomination for portraying Aragorn/Strider in The Lord of the Rings: The Fellowship of the Ring.
Frodo played by Elijah Wood is actually the lead of the film but Frodo is not physically imposing and his main method is to avoid danger rather than face it. Aragorn comes along as their guide some time in their film and tries to help them best he can. In McKellen's review I said that he made the character exactly as I pictured him when I read the book, Mortensen's Aragorn is not exactly how I pictured the character, but nevertheless his take on the character still is successful. Mortensen plays Aragorn quite effectively as most certainly a hero in the film yet not a perfect hero which is essential for his character's path that moves across all three films.
Mortensen's quite good showing strength well at the same time concealing greater strength. One of the biggest aspects of his character is the shame he feels due to the actions of his ancestors, and Mortensen brings this into his performance by showing a certain distance in his heroics. Yes Aragorn is a completely heroic character literally throwing himself into danger to save others, but still his manner with others withdrawn and hesitant. Mortensen makes a nice balance showing exactly how he became the ranger in that he does not have the strength to fulfill his destiny yet will still will do whatever good he can in his own way.
Mortensen delivers a very important need in terms of the film is that he stands as certain support to Frodo and the others. He is strong but far from perfect. When he shows up he is able to help the hobbits but he does not really act as a comforting factor which properly keeps the intensity of those that threaten the hobbits. Mortensen is a strong presence and always believable in the action scenes honestly showing an effort in them. His work adds nicely to the tapestry of this film as well the whole trilogy where his character arc lies. He may not quite be the highlight of any of the films, but is one of the highlights of the epic trilogy.
Boromir easily could be just a bully frankly whose want for power is pretty blunt, but Bean does not portray him as such. Bean has him very close to Aragorn actually, but with the key difference being that Boromir is a far more emotional man whose pride can override his better judgment. Bean importantly in any of the moments where he speaks of his homeland has a great intensity in this pride. We can even sense his feelings of both accomplishment and even sadness in what he and his people have been doing and what they have lost to protect the rest of the world from the forces of evil. Bean is great in honestly creating a history in the man, a man who has faced the evil directly for so long on the front lines, and cannot forget that.
Whenever Boromir speak of the ring and his own ideas for it, it never is of evil or greed. Bean is quite effective in the way Boromir seems drawn to in such a primal way, but is almost poetic in the manner in which he speak of the ring. Although he may be wrong about the ring Bean never shows his fallacy to come from evil. Instead Bean has such a genuine passion in what he speaks about, he shows him as a man who honestly believes that the ring will save his land and his people he cares so much for. When Boromir does finally betray his pledge to help Frodo in an attempt to steal the ring for himself Bean is excellent portraying it as an act of desperation above else, and importantly afterwards allows us to see the sadness in Boromir that comes when he realizes what he does.
Bean's absolute devotion in the part when it comes to realizing that underlying motivation of the man humanizes Boromir beautifully and even manages to show just how it was his overpowering emotions rather than evil that drives him to attempt to steal the ring. Bean finds a truth in the character that makes his final scene far more powerful than it would be otherwise. I personally love his reactions in his last stand as he fights on even it becomes quite clear he is losing the fight. Bean's has such heart in his expressions showing the last stand of a man who will try to his last breath. Bean makes Boromir's final moments quite poignant in creating this man who deep down inside only did desire good in his soul. In close examination this is great work that turns what could have been just a simple display of a prideful idiot, into a tragic portrait of a true patriot.