There's always something exciting about finding a new film-maker. In the last couple of years, arthouse audiences in this country have become better acquainted with the likes of José Guerin, Lisandro Alonso and Mahamat-Saleh Haroun, who were celebrated on the festival circuit before finally securing a theatrical release. However, few of the current crop of directors awaiting discovery are as intriguing as Eugène Green, a 63 year-old maverick whose fourth feature, The Portuguese Nun, opens this week at The ICA in London.

Born in New York in 1947, Green quit what he now calls `Barbaria' to live in West Germany and Czechoslovakia before settling in Paris in 1969. Fluent in French, German, Czech and Catalan (and he's learning Basque), he devoted himself to the study of Baroque literature and began writing his own novels (many of which went unpublished) plays. In 1977, he founded the Théâtre de la Sapience to renew contemporary drama by rediscovering the modernity of the 17th-century aesthetic.

However, it took another two decades before Green was finally able to bring this distinctive sensibility to the screen. He made his debut with Toutes les nuits (2001), which starred Alexis Loret and Adrien Michaux in an reworking of Flaubert's A Sentimental Education that transferred the action from the revolutions of 1848 to the May Days of 1968 and drew heavily on the cinematic influence of Robert Bresson and Manoel De Oliveira. His follow-up couldn't have been more different, however, as Le Monde vivant (2003) cast a fairytale about knights, maidens, an ogre and a lion (that was really a Labrador Retriever) in blue jeans and stylised slang.

Green ventured back into reality for Les Pont des Arts (2004), which follows the contrasting fortunes of conflicted students Adrien Michauz and Camille Carraz and hesitant scholar Alexis Loret and his mezzo-soprano girlfriend Natacha Régnier, who is being courted by sinister impresario Denis Podalydès. This time, however, the customary nods to Bresson and De Oliveira were tempered by a provocative wit that recalled Raul Ruiz, while the music of Monteverdi reinforced the richness of dialogue worthy of Jacques Rivette or Eric Rohmer. And this compelling combination of art, artifice and asceticism recurs in The Portuguese Nun. Ravishingly photographed by Raphael O'Byrne in a mesmerising series of slow pans and abrupt close-ups, this paean to Lisbon is a billet doux to Lusitanic cinema, in which Green not only pays handsome homage to Manoel de Oliveira, but also tests the very limits of self-reflexivity.

French actress Leonor Baldaque checks into a hotel for the location shoot of Green's adaptation of Gabriel de Guilleragues's 17th-century epistolary novel, Letters of a Portuguese Nun. The desk clerk is anything but impressed and even Baldaque's make-up artist thinks the project is a pompous bore aimed solely at preening intellectuals. While acclimatising herself with the city, Baldaque befriends orphan Francisco Mozos, accepts a dinner date from lonely aristocrat Diogo Dória and becomes fascinated by the contemplative stillness of nun Ana Moreira, as she prays through the night in a nearby church. However, she is briefly distracted by a fling with handsome co-star Adrien Michaux, who lures her into bed with protestations that his marriage is a sham.

Sensing Baldaque's fragility after Michaux's departure, Green tries to cheer her up by taking her to a fado bar. But, as he disco dances alone, Baldaque slips back to the candlelit church to engage in an earnest theological debate with Moreira. Next day, she seeks out Mozos's hard-pressed foster mother, Beatriz Batarda, to ask if she would have any objection to her adopting the boy and they strike a deal that's mutually beneficial.

Strewn with long silences and even longer takes, this is an idiosyncratic reverie on love and faith, film and life. Yet it's also mischievously poetic and singularly moving. Searching for personal as well as professional fulfilment, the atheistic Baldaque exudes a wistful aura of psychological and spiritual inadequacy and her seemingly disparate encounters bring her inexorably closer to a deeper understanding of herself and her purpose. Some will bridle at the highly stylised minimalism, the cerebral chapter headings, the meta-cinematic friskiness, the surfeit of literary and filmic references and the extended fado interludes. But this is a deceptively passionate and poignant picture that will enchant those prepared to surrender to its deadpan charm.

Another young woman struggles to find her niche in Isabelle Czajka's Living on Love Alone, as twentysomething Anaïs Demoustier leaves college with a clutch of qualifications, only to discover that they are next to no use to her in the demoralising and desensiting world of work. However, what starts out as a mischievous satire on Sarkozyian mores descends disappointingly into spurious melodrama, as the scene shifts from a bijou bedsit in Paris to a rustic hideaway on the Spanish border.

Ignoring the warning of estranged father Jean-Louis Coullo'ch, the 23 year-old Demoustier heads for the capital brandishing her communications degree and brimming with confidence that she's going to breeze into a trendy advertising agency and become an overnight sensation. However, boss Océane Mozas delegates her to supervise food orders for her colleagues and frequently asks her to babysit her precocious kids. Lucky to escape with a ticking off after losing the daughter during a trip to Euro Disney, Demoustier finally snaps after she is sent to collect boxed lunches from a nearby café and is then excluded from the subsequent meeting.

Finding a new job proves trickier than she expected, however, and her mood after stints with a publishing company and a photo processing shop is not improved by a frosty encounter with her fretful mother, Christine Brücher, and disapproving brother, Manuel Vallade. Taking solace in casual pick-ups at soulless nightclubs, Demoustier eventually lands a job as a door-to-door salesman with Laurent Poitrenaux. But, once again, she quickly realises she is not cut out for hard-nosed cold-selling and receives a stern dressing down for looking through a lonely customer's photo albums instead of going in for the kill.

Poitrenaux instantly repents his harsh criticism and beds Demoustier in a cheap hotel. But he still fires her and she hooks up with aspiring actor Pio Marmaï, whom she had met during a role-playing exercise during her interview. Despite being less well educated, Marmaï seems to share Demoustier's worldview and she willingly agrees to join him on a jaunt into Spain to deliver a car to an unseen client. However, the vehicle is being watched by customs and their brief sojourn in the sun-scorched countryside comes to a dramatic end in a supermarket car park.

Demoustier has already shown herself to be a rare talent in Anne Novion's Grown-ups (2008), Juliette Garcías's Be Good (2009) and Olivier Coussemacq's Sweet Evil (2010) and she superbly captures the supercilious certitude of youth, as she banks on her looks and intelligence to launch herself up the career ladder. Yet she also conveys a touching fragility that causes her to settle for debasing one-night stands with older men and a reckless naiveté that prompts her to accompany Marmaï on a mission she suspects is dangerously illegal.

Marmaï and Poitrenaux show well as the superficial charmer and the seedy seducer. But too many other characters are sketched cyphers, whose haughty professionalism only hints at the rigidity of French working practices and the difficulty that the `me' generation has in accepting them. Yet the Parisian sequences have a tangible credibility that is utterly absent from the denouement, which feels as though it belongs to another picture altogether.

It could be argued that Czajka is seeking to show that dreams of escape and romantic bliss are just as unlikely to come true as unrealistic job ambitions. But, despite cinematographer Crystel Fournier's accomplished contrasts of the stifling interiors and inviting vistas, the shift into A Bout de souffle territory is wholly unconvincing.

Demoustier has the look of a young Jennifer Love Hewitt, who took the title role in the 2000 teleplay, The Audrey Hepburn Story. And the Belgian-born actress essays another free spirit seeking a little direction in Breakfast at Tiffany's, which is being released in cinemas to mark the 50th anniversary of its 1961 premiere - an event made all the more poignant by the recent passing of director Blake Edwards.

Author Truman Capote allegedly wanted Marilyn Monroe to play Holly Golightly, whom he had modelled on Gloria Vanderbilt, Oona O'Neill and Carol Marcus (the last of whom were respectively the wives of Charlie Chaplin and Walter Matthau). But it's now impossible to see anyone other than Hepburn sitting on a window ledge and strumming a guitar as she addresses `Moon River' to the skies above New York City.

Living with her unnamed ginger cat in an Upper East Side brownstone, Holly drives upstairs neighbour Mr Yunioshi (an unfortunately miscast Mickey Rooney) crazy with her scatty ways. But she enchants mobster Sally Tomato (Alan Reed), whom she visits in Sing Sing once a week, and struggling novelist Paul Varjak (George Peppard), who is the protégé of married socialite Mrs `2-E' Failenson (Patricia Neal).

However, during a chance encounter with Texas vet Doc Golightly (Buddy Ebsen), Paul discovers that Holly was born Lulamae Barnes and that she married the widowed Doc when she was just 14 years old. The union didn't last and, on coming to the Big Apple, she fell under the spell of Hollywood agent OJ Berman (Martin Balsam), who coached her in the graces that have persuaded playboy Rusty Trawler (Stanley Adams) to woo her and Brazilian millionaire José da Silva Perriera (José Luis de Villalonga) to propose marriage.

Holly is taken with Paul and they spend a delightful day together that includes visits to various department stores and a library. But she only realises her true feelings for him when José disowns her after she is accused by a newspaper of smuggling drug-running information to Sally on behalf of his mob buddies.

Much has changed in the half-century since this chic melodrama first appeared. Good-time girls like Holly are nowhere near as shocking or rare and the decadence depicted in the powder rooms and swanky niteries now seems rather tame. But many still set great store by material possessions like Tiffany jewellery and little black dresses by Givenchy and the film is almost certain to receive a warm welcome from fashionistas and nostalgics.

But, churlish though it may seem to carp, this is not a classic picture. Indeed, beside Henry Mancini and Johnny Mercer's Oscar-winning song, Franz Planer's Technicolor photography and Putney the cat's hang-mog expressions, its cachet owes little to its cinematic qualities. Not only does George Axelrod's screenplay bowdlerise its source and rose-tint Holly's sordid existence, but Hepburn's performance is mannered and she has no chemistry whatsover with the stolid Peppard.

Then there's the question of the hideous stereotyping of the Japanese photographer, which continues to scuff the escutcheon of the otherwise exemplary career of the undervalued Mickey Rooney. Thus, this is a love song to consumerism, superficiality, unrealistic expectation and settling for second best rather than one of the great screen romances.

The last of this week's young ladies uncertain where they're hiding walks into a nightmarish situation in Steven R. Monroe's remake of the notorious 1979 shocker, I Spit on Your Grave.

With original director Meir Zarchi serving as executive producer, this is clearly a conscious attempt to re-examine the issues raised by the subject matter and the reception of the original film. However, the proficiency of Monroe's direction pushes this much closer to torturtainment than a sickening assault on the viewer's sensibilities that forces them to confront the extent to which they become a complicit voyeur in watching both the rape sequences and the revenge killings.

Arriving in the backwoods to work on her new novel in an isolated cabin, Sarah Butler misses her turn and falls foul of gas jockey Jeff Branson after accidentally humiliating him in front of guffawing buddies Daniel Franzese and Rodney Eastman. So, a couple of days after Butler gives autistic plumber Chad Lindberg a grateful peck on the cheek for unblocking her toilet, Branson arrives in the dead of night to teach the city snob a lesson. Butler manages to escape into the woods after Lindberg has been bullied into raping her and she stumbles across sheriff Andrew Howard. He escorts her home. But, rather than being her saviour, Howard proves to be as sadistic as her attackers and what follows is brutal and harrowing and Franzese records it all on a camcorder, in case anyone misses the action's accusatory self-reflexivity.

The twist comes when Butler jumps off a bridge into the river before the rednecks can finish her off and they convince themselves that her body has disappeared and that they have gotten away with their crime. But Butler returns to use the shack she noticed while out jogging for a series of pitiless killings involving a noose, some quicklime, two fishing hooks and a strategically placed rifle.

Neil Lisk's photography and Jason Collins's effects make-up are highly creditable and Monroe not only builds the situation astutely, but he also shifts the emphasis away from the deed and on to the aftermath. However, Butler singularly fails to convince as a successful writer and, more damningly, struggles to suggest the necessary extremes of emotion, either during her cruel torment or her flint-hearted retribution. Conversely, the perpetrators veer between pantomimic and pathetic, with their both their savagery and their suffering feeling more contrived than sickening.

The old questions will be asked about the necessity of showing the violation and the slaughter in so much detail and about whether this is a cynical piece of exploitation or an exercise in female empowerment. But what most needs answering is why American horror has become so stuck in a tedious cycle of torture porn and dubious remakes that exposes its moral abnegation and its creative bankruptcy.

It's something of a relief, therefore, to end the week by returning to North London for yet another tale of romantic frustration. Running just 75 minutes, Honeymooner is as modest as writer-director Col Spector's debut, Someone Else (2006). But it's also as droll and perceptive in its insights into being a single male in world that not only baffles him, but also seems to have something against him. Dumped by fiancée Lisa Faulkner just weeks before their wedding, Gerard Kearns is reluctant to accept the advice of pals Chris Coghill and Al Weaver and indulge in some meaningless sex. Indeed, he is appalled by the antics of both, as Weaver keeps flirting with strangers even though he's supposed to be contemplating marriage to Georgia Broaders, while Coghill is cheating on new girlfriend Daisy Haggard with Billie Higson, a 17 year-old who had stroked his ego by praising a documentary he had directed .

However, everyone around Kearns seems to be behaving oddly. Having failed in a gauche attempt at seducing him to heal her own broken heart, fortysomething Spanish neighbour Montserrat Roig de Puig coaxes him into chatting up girls at a local bar, while Haggard invites him out for a night's drinking and proceeds to kiss him in the taxi on the way home.

Unfortunately, however, Coghill takes a dim view of this brief encounter and Kearns (who is nursing a back injury after a yoga class) finds himself ostracised from his increasingly misshapen circle. But a chance meeting with old school friend Wunmi Mosaku at rabbi Simon Schatzberger's soup kitchen seems to suggest that things might have taken a turn for the better.

This may not be the most original or sophisticated picture and the ending is clumsily bromidic. The performances are pretty mixed, but Kearns is genially perplexed, whether he's guzzling down red wine and mood pills or climbing out of pub windows to escape disastrous dates, while Haggard exudes ditzy allure, as she seizes upon someone else's vulnerability to feel better about her own. But Spector avoids the bulk of Britcomedic clichés in showing how most people manage to muddle their way through romantic dalliances without the wit and eloquence of characters in a Woody Allen or Eric Rohmer film.