There are some films that cause you to wince simply by reading the synopsis. Take, for example, the tale of a creepy nerd in a small US town, who sends off for a designer sex doll and proceeds to pass it off as his girlfriend. But, far from being another sniggering piece of teen-targeted smut in the Superbad mould, Craig Gillespie's Lars and the Real Girl is an utterly charming study of crippling loneliness, unspoken affection and community spirit. Refusing to mock its admittedly far-fetched premise, this is a paean to a plastic Pollyanna who makes everybody feel better about themselves and each other. Frank Capra couldn't have done it any better.

Following on from his Oscar-nominated performance in Half Nelson, Ryan Gosling reinforces his reputation with an affecting insight into private pain and social awkwardness that is more than matched by Paul Schneider and Emily Mortimer, as the brother and sister-in-law whose reluctant adherence to the advice of the family doctor (Patricia Clarkson) persuades their neighbours to indulge Gosling's conviction that Bianca really is a wheelchair-bound Brazilian-Danish missionary on a sabbatical to experience the world.

The sequence in which the locals find jobs that Bianca can do to show Gosling how much she's been accepted could have been risible. But, such is the sensitivity of Nancy Oliver's screenplay and Gillespie's direction that the ensemble's enthusiasm feels as authentic as it's heart-warming. Even the potentially winsome subplots involving Gosling's chorister workmate Kelli Garner and his fears for Mortimer's pregnancy ring true, as do the asides on resolving trauma and accepting responsibility.

Curiously, this week also sees the release of another loner saga, although this time the ending is nowhere near as cosy. Yet for all its sinister simplicity, there's something deeply moving about Lenny Abrahamson's Garage, which features an exceptional performance by Pat Shortt as the ungainly innocent who runs the petrol station in a stagnating hamlet in mid-West Ireland.

Proud of serving his community and blissfully unaware he's a figure of fun to the guys in the pub and an irritant to shopkeeper Anne-Marie Duff, Shortt is happy in his own little world, feeding a farmer's horse with apples and bantering with trucker George Costigan about sexual matters he doesn't really understand. However, he's tempted to court favour with bashful new assistant Conor J.Ryan and his teenage pals and his naivety is misinterpreted as malignancy by acquaintances whose willingness to judge says more about themselves than Shortt's muddled motives.

As in the underrated Adam and Paul, Abrahamson combines moments of hilarity and melancholy with a sure sense of the outsider psyche. And no one will deliver a more poignant denouement this year.

Following his triumph with U-Carmen eKhayelitsha, Mark Dornford-May seeks to assess how traditional beliefs can survive in a modern milieu in Son of Man, which shifts the New Testament story to the fictional African state of Judea at a time of military occupation, sectarianism, violence and poverty.

Chronicling the life and death of Jesus (Andile Kosi), it's infinitely more successful in re-imagining its biblical material than Penny Woolcock's arch bid to relocate Moses to Margate in the dismal Exodus. But it also occasionally strains credibility - most notably when cutting away to English-language news bulletins and in its depiction of the miracles and the Crucifixion - and it uneasily errs on the side of political correctness by including some female apostles. But the mix of protest and preaching is often inspirational and both Kosi and Pauline Malefane (as the Virgin Mary) make the most of the amazing Xosa choral score.

Music is also key to Four Minutes, as the prison authorities detaining murderess Hannah Herzsprung resist 80-year-old music teacher Monica Bleibtreu's insistence that she has the potential to become a great pianist, especially after she assaults weasly guard Sven Pippig during her first lesson. However, Bleibtreu earns Herzsprung's trust and they discover more about each other as they travel to outside competitions. But while Bleibtreu learns about her prodigy's dead baby and her abusive father's certitude of her innocence, she refuses to divulge anything about her own past as a lesbian nurse whose Jewish lover was cruelly executed during an Allied air raid on a concentration camp.

This revelation risks tipping a finely balanced, if somewhat predictable, character study into melodrama. But director Chris Krause redeems the story with a finale that's riven with anti-heroic self-destruction and a crushing sense of the futility of existence.