In East Germany in 1989, commited socialist Christiane collapses when she sees her son Alexander being beaten by police whilst taking part in a demonstration. She spends eight months in a coma, during which the Berlin Wall falls and the old East is transformed by the invasion of capitalism: her flat has new furniture, Alexander now sells satellite dishes for a living and her daughter Ariane has taken a job at Burger King. When whe wakes, the doctors warn Alexander that even a slight shock could kill her, and he sets about protecting her from the reality of the unified Germany, retro-fitting the bedroom to which she is temporarily confined, faking news broadcasts and even bribing children to sing songs of the old Republic at her bedside.

There is a truly glorious moment that occurs early in the second half of Wolfgang Becker's hugely entertaining comedy-drama. With Ariane out of the flat and Alexander asleep in the chair by her bed, Christiane discovers that she is now strong enough to walk and curiously ventures outside. Signs of the new capitalism are everywhere, and as she wanders along the street, increasingly bemused by what she is seeing, a helicopter rounds the corner, transporting a large statue of Lenin to who knows where. As she watches in disbelief, the statue glides past, rotating slowly to face her as it does so with it's right arm outstretched, a disassembled symbol of her own lost past seemingly reaching out for help, but also looking uncannily like an angel beckoning her to the socialist heaven that the shock of this very experience is in danger of transporting her to. Despite the quality of so much of what has came before, this moment is close to cinematic perfection, in its imagination, its boldness and its execution (as the statue passes Christiane, the camera glides round behind her in an electrifyingly effective circular track). So easily could this scene have just been a step too far, and the crystal-delicate balance of drama and comedy that Becker has spent an hour perfecting could have been shattered. But he pulls it off so sublimely that from this point on he can seemingly do no wrong. Well, almost.

Good Bye, Lenin! arrived in the UK with its comedy credentials to the fore, often accompanied by a somewhat stereotypical surprise at the concept of anything funny emerging from Germany. Presumably these people were unaware of the delightful and very funny Life is All You Get, a 1997 film directed by – well what do you know? – Wolfgang Becker. As it happens, it's the drama that is up front for the first part of the story, and what gives the whole film its emotional and narrative core. The comedy emerges from the dramatic structure, and though at times it verges on the absurd, it somewhat miraculously never completely strains credibility – there is always a sense that, given this situations and these characters, this could just happen.

What sells this most convincingly are the performances, most especially Daniel Brühl as Alexander, whose devotion to his mother, obsession and then love for Russian nurse Lara and increasingly complex methods of protecting Christiane from the reality just outside her bedroom window are portrayed with conviction, energy and a sometimes wonderfully deadpan humour. It is Alexander's ingenuity that provides some of the film's most delightful sequences. Having redressed the flat as it once was, he supplies his mother with her favourite East German foods by transfering imported goods into old jars rescued from waste bins, and only allowing her to watch TV when he is able to feed it with video recordings of pre-transformation news broadcasts. Later, he even creates new ones with his work colleague and video-mad friend Denis, whose ambitions to be a film director prompt him to cut part of a wedding video in the style of the bone-to-spaceship transition in 2001: A Space Odyssey (a second nod to Kubrick has Alexander and Denis retro-fitting Christiane's bedroom in a speeded up wide shot to an accelerated version of The William Tell Overture, directly referencing a memorable sequence in A Clockwork Orange). This is all at its funniest when the cracks start to show, a huge Coca Cola banner unfurled on the side of the building opposite prompting a hilarious mock news item from Denis and Alexander to explain it away.

Of course, it's the national politics that give the film a historical and socio-political edge, or at least how they are handled by Becker and his co-scriptwriter Bernd Lichtenberg. It would also mark it soundly apart should there ever (groan) be a US remake, which in the tradition of modern American mainstream movies (and presidents) too often see things in black and white terms, and would no doubt clunkily and scornfully parody life under Communism and just as clumsily celebrate the wonders of the Capitalist takeover. Becker's more sophisiticated approach manages to both mock and celebrate aspects of both. Cristiane's early enthusiasm for her Fatherland, for her students and for writing reprimanding letters is shown as over-enthusiastic, but is never portrayed as sinister or damaging, and the arrival of Burger King and satellite dishes is seen to offer choice to the consumer and yet still be somewhat superficial to everyday life. Alexander himself has embraced many aspects of the new capitalism, but his efforts to protect his mother from the truth with often complex deception employs many of the techniques of information control practiced by his former goverment, and in the process he learns skills that could have landed him a top position in the Ministry of Information. Increasingly for Alexander, the old ways seem preferable to the new, but he has created his own version of the past, one that never really existed in the world outside.

Despite the comedy, Becker is still making a drama of family love and unity, and towards the end moves firmly back into that mode, delivering a perhaps cynical twist that left me (and at least one major character) feeling more than a little betrayed. Frankly, this kicks uncomfortably against much of what has gone before, and in a way that temporarily pulled me out of the film. It is to Becker's credit that he got me through this and pulled me back in for a superb final fifteen minutes, and a genuinely uplifting voice-over from Alexander as he examines his own memories and sense of loss, and the positive aspects of everyday socialist thinking. I, and all those around me in the packed cinema, emerged from the screening intellectually and emotionally satisfied, and with huge smiles on our faces.