Obsession (1949) 

Methodical psychiatrist Robert Newton determines to take revenge on adulterous Sally Gray by committing the perfect crime. Conjuring a suitably twisted atmosphere from the spare sets and stark locations, tension is gradually built and character relationships well etched.

Obsession (1976

Stylish visual command and swirling chords of Bernard Herrmann's unmistakable score power less secure narrative with somber Cliff Robertson encountering double of wife Geneviève Bujold, killed years earlier in kidnapping. Romantic melodrama mimics masterful Vertigo, yet lacks wit and tragic yearning. 

October Gale (2014) 

Character study in loss masquerades as thriller with consumed Patricia Clarkson facing memories of deceased husband in remote lakeside home until bleeding Scott Speedman appears with storm and vengeful Tim Roth closing in. Artfully serious, narrative finally crumbles without tension or resolution.

Oculus (2013) 

Obsessed Karen Gillan and recovering Brenton Thwaites are siblings facing up to possessed mirror and childhood events that led to parents' deaths. Stylish understatement and melding of past and present brew unnerving atmosphere even if end feels more elongated tease than dark resolution.

The Odd Couple (1968) 

The strength of Neil Simon's writing and the vitality of Jack Lemon and Walter Matthau's personification of neurotic Felix and slobbish Oscar maintain the comedy and even empathy. Effectively a series of carefully honed set pieces, including the always delightful arrival of the Pigeon sisters.

Odd Man Out (1947)

At once a socio-political reflection of its time, more vitally a reflection of the human condition, of dreams and ambition and love. Classic cinematic artistry, William Alwyn's glorious score and sublime performances make this essential viewing in any age.

Odds Against Tomorrow (1959) 

Cynical, bitter noir, as jaundiced ex-cop Ed Begley recruits edgy gambler and jazz musician Harry Belafonte as well as violent war veteran Robert Ryan to rob suburban bank. Racial tensions and gloomy desperation infuse expressive visuals & bleak tension.

Of Human Bondage (1934) 

More of a historical curiosity than a cohesive narrative, fragments of a storyline see Bette Davis' self-destructive waitress threatens to drag down Leslie Howard's idealistic Englishman. Isolated visuals and scenes maintain some potency.

Official Secrets (2019) 

Low key detail and character definition aids edgy, slow-burn tension of spy agency translator Kiera Knightley's decision to reveal UK government deceit leading to 2003 Iraq War. Confluence of journalistic, political and personal concerns absorbingly held together by able cast and adept storytelling.

Ofrenda A La Tormenta (Offering To The Storm) (2020) 

Final film in trilogy revolving around Marta Etura's tormented police inspector, a cleverly conceived fusion of the procedural and supernatural culminating with a satisfying conclusion. Amping up the shocks as well as the visual sheen, a seamless and intense thriller that accentuates the emotional.

Ohjik Geudaeman (Always) (2011) Lit up by soulful, vital Han Hyo-joo as a blind woman in a relationship with angry boxer seeking redemption, So Ji-sub, persuasive style and integrity keeps melodramatic excess mostly in check. Third Act twists push emotional rawness to the edge.

Okja (2017) 

Scattershot satiric savagery coupled with assured visuals and convincing FX provides ultimately uneasy companion, as tone dials from melodrama to shrill comedy to animal rights message. Girl tries to rescue her friend, a genetically modified superpig. Impressive set pieces.

Old (2021) 

Enclosed sense of dread and comedy terror as time passes at an accelerated rate for tourist group stranded in idyllic cove, falters with thin characters and unsure pacing. Revelations and final twist neither enrich mystery or paper over holes, concept and narrative stretched beyond effective limits.

Old Guard (2020) 

Muscular, violent action sequences and glossy visuals can't disguise a laborious narrative arc, reliant on character angst and melodrama. Without a distinctive view or leavening humour, Charlize Theron and her other immortals struggle to bring humanity to the emotions.

Old Henry (2020) 

Low key character study framed with open space, widescreen visuals as the appearance of a stranger forces reflective farmer Tim Blake Nelson to confront his past and legacy. Anchored by commanding lead, simmering tension unsurprisingly explodes into violence.

Oliver Twist (1948) 

Exciting blend of evocative visuals, narrative twists and incisive characters, equal parts dark and eccentric as Oliver navigates desperate London streets. Taut construction highlights Alec Guinness' devious Fagin and Robert Newton's brutal Sykes. Crafted with artful emotion.

The Omega Man (1971) 

Very much a product of its time, with a curiously flat visual style, brittle sound and clunky dialogue. The empty hopelessness again provides some effective moments and the ending expands on The Last Man On Earth's church finale, with crucifixion  imagery. 

Once Upon A Dream (1949) 

Inoffensive trifle never builds needed head of comedic steam as lightheaded Googie Withers fantasizes about practical Griffith Jones, her demobbed husband's army batman. Commentary on stresses with post-war economy and rebuilt relationships lost amid surface farce.

Once Upon A Time In Hollywood (2019) 

Loose, meandering and affectionate view of LA and film making that seeds the Manson family background for a typically vicious and fiery climax. The pleasures of visual design, playful dialogue and the easy lead performances are a delight. 

Once Upon A Time In The West (1968) 

From the opening shoot-out to the final, indelible shots, a classically framed tale of power and revenge, so full of the glorious, giddy potential of cinema (picture, sound, design, music) that each viewing is essential. A sun-blasted elegy for the western.

One Of Our Aircraft Is Missing (1942) 

Combining the naturalistic with the poetic, the escape of British airman across occupied Holland features tense sequences alternating with determined propaganda. Thoughtfully conceived characters, especially Pamela Brown and Googie Withers' strong, commanding women.

One Way Street (1950) 

Jaded doctor James Mason is doomed the moment he escapes with sneering gangster Dan Duryea's stolen money and icy girl Märta Torén, even as he reaches for love and redemption in remote Mexican village. Appealing cast stymied by uneven plotting and diffused tension.

Only The Brave (2017) 

With intoxicating images that simultaneously capture the beauty and danger of fire, a technically consummate production with likeable performances building a close sense of community and deepening true-life tragedy. A finely crafted tale that dovetails epic heroism with personal loss.

Only The Valiant (1958) 

Sturdy production punctuated by brutal sequences sends stoic captain Gregory Peck on suicide mission to hold pass from Apaches while dealing with own mistrustful troop. Sturdy support cast and solidly involving without rising above the surface thematically or emotionally.

Open Range (2003) 

Solidly involving, old fashioned western that misses the mythic while delivering on the emotional as Robert Duvall and Kevin Costner's cattle drivers seek a place to call home. Evocative visuals and score, controlled and expansive, with a dynamic shoot out.

Operation Finale (2018) 

A solid, involving character piece fronted as a thriller as Oscar Isaac's Mossad agent puts together a team to kidnap Ben Kingsley's Nazi war criminal from Argentina and bring him to trial. Characters are smartly drawn, the production unfussy if also rather dry.

Operation Mad Ball (1957) 

Amiably disposable, some snappy dialog and spirited performances make most of minimal setup as cunning soldier Jack Lemmon conspires to throw a party in post-war France, deceive captain Ernie Kovacs and win affection of nurse Kathryn Grant. Polished delivery. 

Operation Mincemeat (2022) 

Intrinsic fascination and tension within outlandish World War II plot to fool Germans about Allied invasion, hampered by sprawling, dry style and redundant romantic sub-plot. Nicely detailed, personably performed, sparks of humour pierce stoic British atmosphere.

The Operative (2019) 

Efficiently produced and styled, flashback structure dissipates tension despite blend of vulnerability and toughness from Diane Kruger's spy in Iran, finally fighting for a way back to normality. Individual sequences supply controlled thrills, even as tone and shady characters remain drily inaccessible.

Orage (A Stormy Summer Night) (2015)

Atmospheric, strongly performed drama of identity and belonging never quite delivers emotional punch as conflicted Marina Foïs escapes stifling normality with murderer on the run Sami Bouajila. Social and narrative concerns remain unresolved.

The Other Zoey (2023) 

Smart, wary computer student Josephine Langford believes in compatibility rather than romance until mistaken identity throws her together with genial, school sports jock Drew Starkey. Spirited cast and cheerful style enliven entirely predictable and demure story. 

Otherlife (2017) 

Enjoyably twisty and twisted virtual reality thriller as obsessive Jessica De Gouw develops a mind-bending biological serum that expands time, only to find herself fighting for control of the invention. Sleekly produced, neatly combining the personal with genre thrills.

Our Man In Havana (1959) 

Formidable cast and fluid Cuba visuals enliven wry comic take on spies and spying as Alec Guinness' vacuum salesman is recruited by Noël Coward and finds his fictitious reports have deadly consequences. Languid pacing builds to dramatic threat and pleasingly caustic resolution.

Out Of The Past (1947)

Weary, manipulated Robert Mitchum caught between jealous hood Kirk Douglas and devious lover Jane Greer is caught in a labyrinthine plot of murder and double-cross. Evocatively framed and designed, drenched with a sleek atmosphere of dark cruelty and sexual melodrama.

Out Of Time (2003)

Small town Florida chief of police Denzel Washington becomes entangled in corruption and murder, trying to hide evidence from estranged wife, tolerant detective Eva Mendes. Attractive locations and performers allied to tight, polished rhythm maintain interest even when credulity is snapped.

The Outlaw Josey Wales (1976) 

A finely crafted story of revenge, family and redemption, simply but evocatively shot and balanced with a sense of humour. Savage bursts of violence are likewise contrasted with moments of sensitivity as characters reveal depth and humanity. An enduring classic.

Ouvert la nuit (Open At Night) (2016) 

Appealing, humorous, affectionate view of theatre people as a producer and his intern buzz around Paris to find a chimpanzee for the new show and enough money to get to opening night. At times too self-consciously surreal, yet maintains a looseness that is winning.

Oxygène (2021) 

A groggy Mélanie Laurent grows increasingly desperate as oxygen fast runs out in the tomb-like cryogenic unit she finds herself trapped in. A tight thriller that plays on themes of memory and individuality with a fiercely focused solo performance, diminished by soft ending.